JP5655902B1 - Manufacturing method of optical assembly - Google Patents

Abstract

An optical assembly capable of accurately adjusting the optical axes of laser beams emitted from a red LD, a green LD, and a blue LD. A light assembly includes a red LD, a green LD, and a blue LD. Each of the red LD 11, the green LD 12, and the blue LD 13 is mounted on the main surface 30 a of the base member 30 via the submounts 21 to 23. The collimating lens 41 collimates the red laser light LR from the red LD 11, the collimating lens 42 collimates the green laser light LG from the green LD 12, and the collimating lens 43 collimates the blue laser light LB from the blue LD 13. The collimating lenses 41 to 43 are mounted on the main surface 30a via the sub base members 51 to 53. The optical axes of the laser beams LR, LG, and LB are at substantially the same height with respect to the main surface 30a. [Selection] Figure 1

Description

The present invention relates to a method for manufacturing an optical assembly.

  Patent Document 1 discloses a technique related to an optical scanning type image display device that displays an image by two-dimensionally scanning a light beam having an intensity corresponding to an image signal. In this image display device, the first scanning unit and the second scanning unit scan the light beam emitted from the light source unit. Further, a half mirror is provided on the optical path between the first scanning unit and the second scanning unit, and the intensity and timing of the light beam scanned by the first scanning unit and reflected by the half mirror is detected by the light detection unit. Detected by. The first reflecting portion and the second reflecting portion are arranged at the image plane position formed by the light beam scanned by the second scanning portion, and the first reflecting portion and the second reflecting portion are scanned by the second scanning portion. Each light beam is reflected. The optical path of the light beam scanned by the first scanning unit and reflected by the first reflecting unit and the second reflecting unit and reflected by the half mirror is the optical path of the light beam scanned by the first scanning unit and reflected by the half mirror. And enters the light detection unit as the same optical path.

  Patent Document 2 discloses a technique related to a light source device and a head mounted display. The light source device includes a green laser diode, a blue laser diode, a red laser diode, and a dichroic prism that selectively transmits and refracts light therefrom. The green laser diode generates the largest amount of heat and has a large radiator in the light source device. The green laser diode is provided at a position facing the emission port with the dichroic prism interposed therebetween. The width of the radiator is formed to be narrower than the width from the outside of the blue laser diode to the outside of the red laser diode.

  Patent Document 3 discloses a technique related to a multi-wavelength light source device. The multi-wavelength light source device has a plurality of laser diode (LD) chips mounted in a coaxial module, and condenses each emitted light at one point by one condensing lens. The multi-wavelength light source device includes a light source, a condensing unit, and a light guiding unit. The light source includes a plurality of ignition points that emit light. A condensing means condenses the some light radiate | emitted from the some ignition point. The light guide means propagates so that a plurality of lights from a plurality of ignition points collected by the light collecting means are overlapped and mixed.

  Patent Document 4 discloses a technique related to a light source device having a light emitting element such as a light emitting diode. The light source device includes a light emitting element part, a light collecting part, and a multiplexing part. The light emitting element portion includes a plurality of chip-like light emitting elements, and independently controls light emission of each light emitting element through an external terminal. In the light condensing part, the ball lens is held close to the light emitting element in contact with or facing the light emitting element by fitting with the fitting hole provided in the lens stopper, and the light emitted from the light emitting element spreads. The direction is changed to a parallel light flux before it ends. The multiplexing unit has a dichroic mirror and an aperture, multiplexes parallel light beams incident from the condensing unit, and selects and emits a paraxial light beam excellent in parallelism.

JP 2011-227379 A JP 2011-171535 A JP 2011-066028 A JP 2006-013127 A

  In recent years, liquid crystal displays have become widespread, and technological development for application of liquid crystal displays to mobile devices has been promoted. On the other hand, a display using an LD light source is excellent in low power consumption, high definition, and versatility compared with a white LED used for a backlight of a liquid crystal display. For this reason, it has been studied to apply a display using an LD light source to a small projector, a head mounted display, a head up display, or the like. An LD light source employed in such a display has a plurality of LDs constituting three primary colors of light, such as a red LD, a green LD, and a blue LD. A plurality of laser beams output from the LD light source are superposed with each other in order to obtain a colorful image quality.

  However, unlike a general light source such as an LED, an LD light source has a narrow beam divergence angle of about 10 ° × 20 °, for example. For this reason, it is necessary to align the optical axes of the laser beams emitted from the red LD, the green LD, and the blue LD, which is a serious adverse effect on the spread of displays using LD light sources.

  The present invention has been made in view of such a problem, and an optical assembly capable of accurately adjusting the optical axes of laser beams emitted from red LD, green LD, and blue LD, respectively. An object of the present invention is to provide a manufacturing method and an optical assembly.

  A manufacturing method of an optical assembly according to an embodiment of the present invention is a manufacturing method of an optical assembly that combines and outputs red, green, and blue laser beams in three wavelength ranges of red, green, and blue. A first laser diode that emits the first laser light is mounted on the main surface of the base member so that the first laser light included in the first wavelength region is projected onto the first projection point. The first laser beam and the second laser light included in the second wavelength region of the three wavelength regions have the same height as the first projection point with respect to the main surface of the base member. A second step of mounting a second laser diode for emitting a second laser beam on the main surface of the base member so as to be projected onto the second projection point; and a third step of the three wavelength regions. The height of the third laser light included in the wavelength region with respect to the main surface of the base member is first. And a third step of mounting a third laser diode that emits a third laser beam on the main surface of the base member so as to be projected onto a third projection point that is the same as the second projection point. Before or after the third step, a first wavelength filter that transmits the first laser light and reflects the second laser light is used as a base so that the second projection point approaches the first projection point. A fourth step of mounting on the principal surface of the member; a second wavelength filter that transmits the first and second laser beams and reflects the third laser beam; and the third projection point is the first projection point. And a fifth step of mounting on the main surface of the base member so as to approach the projection point.

  An optical assembly according to an aspect of the present invention is an optical assembly that combines and outputs red, green, and blue laser beams, and is the first of three wavelength ranges of red, green, and blue. A first laser diode that emits a first laser beam included in the wavelength band and is mounted on the main surface of the base member via the first submount; and a second wavelength band among the three wavelength bands A second laser diode that emits the second laser light contained in the second laser diode and is mounted on the main surface of the base member via the second submount, and is included in the third wavelength region among the three wavelength regions. A third laser diode that is mounted on the main surface of the base member via the third submount, collimates the first laser light, and passes through the first subbase member. Mounted on the main surface of the base member A collimating lens, a second collimating lens that collimates the second laser light and is mounted on the main surface of the base member via the second sub-base member, and a third sub-base that collimates the third laser light. A third collimating lens mounted on the main surface of the base member via the member, and the optical axes of the first to third laser beams are substantially the same with respect to the main surface of the base member. There is.

  According to the optical assembly manufacturing method and the optical assembly according to the present invention, the optical axes of the laser beams emitted from the red LD, the green LD, and the blue LD can be adjusted with high accuracy.

FIG. 1 is a perspective view showing a configuration of an optical assembly according to the first embodiment of the present invention. FIG. 2 is a top view schematically showing a first step of the method of manufacturing the optical assembly. FIG. 3 is a top view schematically showing a second step of the method of manufacturing the optical assembly. FIG. 4 is a top view schematically showing a third step of the method of manufacturing the optical assembly. FIG. 5 is a top view schematically showing a fourth step of the method of manufacturing the optical assembly. FIG. 6 is a top view schematically showing a fifth step of the method of manufacturing the optical assembly. FIG. 7 is a perspective view showing an appearance of the optical module according to the second embodiment. FIG. 8 is a perspective view showing the internal configuration with the cap of the optical module shown in FIG. 7 removed. FIG. 9 is a perspective view illustrating an appearance of the optical module according to the third embodiment. FIG. 10 is a perspective view showing the internal configuration by removing the glass cap of the optical module shown in FIG. FIG. 11A is a top view of the optical module, and FIG. 11B is a side view of the optical module. FIG. 12 is a perspective view showing a configuration of an optical assembly as the fourth embodiment. FIG. 13 is a diagram illustrating an optical module in which a reflecting member is added to the optical assembly of the third embodiment. FIG. 14 is a perspective view showing an appearance of another optical module according to the third embodiment. FIG. 15 is a perspective view showing an internal configuration of a part (ceramic package) of the optical module. FIG. 16 is a perspective view showing a configuration of an optical assembly as a fifth embodiment. FIG. 17 is a perspective view showing the configuration of the optical module of the fifth embodiment. FIG. 18 is a top view schematically showing a third step of the method of manufacturing the optical assembly of the fifth embodiment. FIG. 19 is a top view schematically showing a fifth step of the method of manufacturing the optical assembly of the fifth embodiment. FIG. 20 is a perspective view showing a configuration of an optical assembly as the sixth embodiment. FIG. 21 is a perspective view showing a configuration of an optical assembly as a seventh embodiment. FIG. 22 is a top view showing a configuration of an optical assembly as an eighth embodiment. FIG. 23 is a top view showing a configuration of an optical assembly as a modification of the eighth embodiment.

  Hereinafter, a method for manufacturing an optical assembly and an embodiment of the optical assembly according to the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
FIG. 1 is a perspective view showing a configuration of an optical assembly 10A according to the first embodiment of the present invention. The optical assembly 10A of the present embodiment can multiplex and output the red laser beam L _R , the green laser beam L _G , and the blue laser beam L _B. As shown in FIG. 1, the optical assembly 10 </ b> A of this embodiment includes a red LD 11, a green LD 12, and a blue LD 13, a first submount 21, a second submount 22, a third submount 23, and a base member 30. Prepare. The base member 30 has a flat main surface 30a.

The red LD 11 is a first LD in the present embodiment, and laser light (first laser light) included in a red wavelength range (first wavelength range) among the three wavelength ranges of red, green, and blue. ) Emit _LR . The red LD 11 is mounted on the first submount 21, and is mounted on the main surface 30 a of the base member 30 via the first submount 21. Red LD11 emits a red laser beam _{L R} with an optical axis along the main surface 30a. Wavelength of the red laser light _{L R} is, for example, 640 nm.

Green LD12 is a second LD in this embodiment, to emit a laser beam (second laser beam) L _G contained in the green wavelength band (second wavelength region) among the three wavelength bands . The green LD 12 is mounted on the second submount 22, and is mounted on the main surface 30 a of the base member 30 via the second submount 22. Green LD12 emits green laser light _{L G} with the optical axis along the main surface 30a. In the present embodiment, the direction of emission of the green laser beam L _G from the green LD12 is at right angles with respect to the emission direction of the red laser light L _R from the red LD 11. Wavelength of green laser light _{L G} is, for example, 535 nm.

The blue LD 13 is the third LD in the present embodiment, and emits laser light (third laser light) included in the blue wavelength range (third wavelength range) among the three wavelength ranges. The blue LD 13 is mounted on a third submount 23 arranged side by side on the second submount 22, and is mounted on the main surface 30 a of the base member 30 via the third submount 23. Yes. In the present embodiment, the emission direction of the blue laser light _{L B} from the blue LD 13, and at right angles with respect to the emission direction of the red laser light _{L R} from the red LD 11, the green laser light _{L G} from the green LD12 Parallel to the emission direction. Wavelength of the blue laser beam _{L B} is, for example, 440 nm.

In the present embodiment, the height H _R of the laser beam emission point of the red LD 11 relative to the main surface 30 a of the base member 30, the height H _G of the laser beam emission point of the green LD 12, and the laser beam emission point of the blue LD 13. as is the height H _B substantially equal to each other, the height of the submount 21 to 23 is set. That is, the laser beam _L R, _{L G,} and the optical axis of the _{L B} are substantially at the same height main surface 30a of the base member 30 as a reference.

  As a constituent material of the submounts 21 to 23, a material having a thermal expansion coefficient close to that of the semiconductor material forming the LDs 11 to 13, for example, AlN, SiC, Si, diamond, or the like is preferable. Each of the LDs 11 to 13 is preferably fixed to the submounts 21 to 23 by, for example, AuSn, SnAgCu, Ag paste, or the like.

  As shown in FIG. 1, the optical assembly 10A includes a first collimating lens 41, a second collimating lens 42, a third collimating lens 43, a first sub-base member 51, a second sub-base member 52, and a third sub-base member. 53, a first wavelength filter 61, a second wavelength filter 62, a fourth sub-base member 54, and a fifth sub-base member 55 are further provided.

First collimating lens 41 is optically coupled to a light emitting end face of the red LD 11, collimates the red laser light L _R emitted from the red LD 11 (collimated) to. The first collimating lens 41 is mounted on the first sub-base member 51, and is mounted on the main surface 30 a of the base member 30 via the first sub-base member 51.

Second collimating lens 42 is a light emitting end face optically coupled with the green LD 12, collimates the green laser light L _G emitted from the green LD 12. The second collimating lens 42 is mounted on the second sub-base member 52, and is mounted on the main surface 30 a of the base member 30 via the second sub-base member 52.

The third collimating lens 43 is optically coupled to a light emitting end face of the blue LD 13, collimates the blue laser light L _B emitted from the blue LD 13. The third collimating lens 43 is mounted on a third sub-base member 53 that is arranged side by side on the second sub-base member 52, and the main surface of the base member 30 via the third sub-base member 53. It is mounted on 30a.

  The optical axes of the collimating lenses 41 to 43 and the optical axes of the LDs 11 to 13 are adjusted so as to substantially coincide with each other. As an example, when the thickness of the submounts 21 to 23 is 0.15 mm and the height of the laser beam emission point of the LDs 11 to 13 is 0.1 mm, the height of the laser beam emission point with respect to the main surface 30a is used. The thickness is 0.25 mm. In this case, for example, when a lens having a diameter of 0.5 mm made of BK7 is used as the collimating lenses 41 to 43, the height of the optical axis of the collimating lenses 41 to 43 is 0.25 mm. Therefore, the optical axis heights of the collimating lenses 41 to 43 and the optical axis heights of the LDs 11 to 13 are substantially the same.

The first wavelength filter 61 is a multilayer filter formed on, for example, a glass substrate, and is mounted on the main surface 30 a of the base member 30 via the fourth sub-base member 54. One surface of the first wavelength filter 61 is optically coupled to the first collimating lens 41, and the other surface of the first wavelength filter 61 is optically coupled to the second collimating lens 42. The first wavelength filter 61, a red laser light L _R collimated by the first collimator lens 41 passes through, and reflects the green laser light L _G, which is collimated by the second collimating lens 42. The optical axis of the red laser light L _R transmitted through the first color filter 61 and the optical axis of the green laser light L _G reflected at the first wavelength filter 61 are adjusted so as to substantially coincide with each other.

The second wavelength filter 62 is, for example, a multilayer filter formed on a glass substrate, and is mounted on the main surface 30 a of the base member 30 via the fifth sub-base member 55. One surface of the second wavelength filter 62 is optically coupled to the other surface of the first wavelength filter 61, and the other surface of the second wavelength filter 62 is optically coupled to the third collimating lens 43. Are combined. The second wavelength filter 62, a red laser beam has reached the first wavelength filter 61 L _R and the green laser beam L _{G (i.e.,} red laser light L _R is collimated by the first collimator lens _41, and the second collimating lens 42 It transmits green laser beam L _G), which is collimated by, for reflecting the collimated laser beam L _B by the third collimator lens 43. The optical axis of the red laser light L _R and the green laser beam L _G that has passed through the second wavelength filter 62 and the optical axis of the blue laser light L _B reflected at the second wavelength filter 62, tuned to substantially coincide with each other Has been.

Incidentally, the basis of the main surface 30a, the height of each center position of the first color filter 61 and the second wavelength filter 62, the laser beam _L R relative to the main surface 30a, light _{L G,} and _{L B} Desirably substantially the same as the height of the shaft.

  Further, each of the collimating lenses 41 to 43 and the wavelength filters 61 to 62 is fixed to the sub-base members 51 to 55 by, for example, Ag paste or solder. The constituent material of the sub-base members 51 to 55 is preferably a material having a thermal expansion coefficient close to that of the collimating lenses 41 to 43 and the wavelength filters 61 to 62 mounted thereon, for example, glass. Alternatively, the sub base members 51 to 55 may be made of ceramic or metal. The area of the mounting surface of the sub-base members 51 to 55 is an area where an amount of ultraviolet curable resin necessary for fixing the collimating lenses 41 to 43 and the wavelength filters 61 to 62 mounted thereon can be applied, for example 0.3. About 0.5 square millimeters is desirable.

In the optical assembly 10A having the configuration described above, the red LD 11, from each green LD12 and blue LD 13, the red laser light _{L R,} the green laser light _{L G} and the respective blue laser light _{L B} is outputted. These laser beams are collimated when passing through the first collimating lens 41, the second collimating lens 42, and the third collimating lens 43, respectively. Then, the red laser light L _R and the green laser beam L _G are multiplexed by the first wavelength filter 61, and the multiplexed light and the blue laser light L _B are multiplexed by the second wavelength filter 62. Red laser light L _R, the multiplexed light of a green laser light L _G and the blue laser beam L _B is emitted to the outside of the optical assembly 10A along a predetermined optical axis.

  Then, the manufacturing method of 10 A of optical assemblies which concern on this embodiment is demonstrated. 2-6 is a top view which shows roughly each process of the manufacturing method of 10 A of optical assemblies.

First, as shown in FIG. 2, the red LD 11 is mounted on the main surface 30 a of the base member 30 via the first submount 21, and the first collimating lens 41 is interposed via the first subbase member 51. And mounted on the main surface 30a (first step). In this step, the red LD 11 and the first collimating lens 41 are arranged so that the red laser light _LR is projected onto the first projection point P1 located on the virtual plane H1 perpendicular to the main surface 30a.

Specifically, first, the red LD 11 is mounted on the first submount 21 and fixed using a normal die bonding method. Then, the first collimating lens 41 is fixed on the first sub-base member 51 while causing the red LD 11 to emit light. In this case, the optical axis of the red laser light L _R is, to be substantially parallel to the major surface 30a, to adjust the vertical position of the first collimator lens 41. As an example, it is preferable to apply an ultraviolet curable resin to the first sub-base member 51 and adjust the vertical position of the collet while adsorbing the first collimating lens 41 with a collet or the like while ensuring its thickness. . Thus, it is possible to adjust the tilt angle of the optical axis of the red laser light L _R for main surface 30a. For example, an imaging device such as a CCD is arranged on a virtual plane that is separated from the base member 30 by a predetermined distance (for example, 1 m) and a virtual plane that is further (for example, 2 m) from the virtual plane, and the red laser light _LR is projected. The vertical position of the first collimating lens 41 may be adjusted so that the position of the point coincides with the horizontal position of the main surface 30a of the base member 30. Since the red laser light _LR is transmitted through the first collimating lens 41, the light beam is substantially parallel light, and it is possible to observe the projection pattern even at a position several m away. is there. After the above steps, the ultraviolet curable resin is cured and the first collimating lens 41 is fixed.

Next, as shown in FIG. 3, the green LD 12 is mounted on the main surface 30 a of the base member 30 via the second submount 22, and the second collimating lens 42 is attached to the second subbase member 52. And mounted on the main surface 30a (second step). In this step, as the green laser beam L _G is projected onto the second projection point P2 located on the virtual plane H1, placing the green LD12 and second collimator lens 42. The height of the second projection point P2 with respect to the main surface 30a of the base member 30 is the same as the height of the first projection point P1 with respect to the main surface 30a.

Specifically, first, the green LD 12 is mounted on the second submount 22 and fixed using a normal die bonding method. Further, the alignment mirror 70 has a reflecting surface perpendicular to the main surface 30a, so that the reflecting surface forms an angle of 45 ° with respect to the optical axis of the red laser light L _R, the light of the green laser light L _G Place on the axis. Then, the green LD 12 is caused to emit light. At this time, the green laser light L _G is projected onto the virtual plane H1. Subsequently, while causing the green LD 12 to emit light, the vertical position of the second collimating lens 42 is adjusted by the same method as in the first step. At this time, the second height of the projection point P2 of the green laser light L _G relative to the main surface 30a, the same as the height of the first projection point P1 of the red laser light L _R relative to the main surface 30a And At this time, it is not necessary to match the positions of the first and second projection points P1 and P2 in the direction parallel to the main surface 30a. After the above steps, the ultraviolet curable resin on the second sub-base member 52 is cured, and the second collimating lens 42 is fixed to the second sub-base member 52.

Subsequently, as shown in FIG. 4, the blue LD 13 is mounted on the main surface 30 a of the base member 30 via the third submount 23, and the third collimating lens 43 is attached to the third subbase member 53. And mounted on the main surface 30a (third step). In this step, as the blue laser beam L _B is projected onto the third projection point P3 located on the virtual plane H1, placing blue LD13 and the third collimator lens 43. The height of the third projection point P3 with respect to the main surface 30a of the base member 30 is the same as the height of the first projection point P1 with respect to the main surface 30a. In this step, the blue LD 13 and the third collimating lens 43 are preferably arranged so that the positions of the second projection point P2 and the third projection point P3 substantially coincide with each other.

Specifically, first, the blue LD 13 is mounted on the third submount 23 and fixed using a normal die bonding method. Further, the alignment mirror 70, the reflecting surface is at an angle of 45 ° with respect to the optical axis of the red laser light L _R, is disposed on the optical axis of the blue laser light L _B. Then, the blue LD 13 emits light. At this time, the blue laser beam L _B is projected onto the virtual plane H1. Subsequently, the upper and lower positions of the third collimating lens 43 are adjusted by the same method as in the first step while causing the blue LD 13 to emit light. At this time, the third of the height of the projection point P3 of the blue laser light L _B relative to the main surface 30a, the same as the height of the first projection point P1 of the red laser light L _R relative to the main surface 30a with a, the position of the third projection point P3, a second position substantially matching the projection point P2 of the green laser light L _G. After the above steps, the ultraviolet curable resin on the third sub-base member 53 is cured, and the third collimating lens 43 is fixed to the third sub-base member 53.

Subsequently, as shown in FIG. 5, the first wavelength filter 61 is mounted on the main surface 30a of the base member 30 (fourth step). In this case, (as is preferred that substantially match) the second projection point P2 of the green laser light L _G is as closer to the first projection point P1 of the red laser light L _R, the angle of the first wavelength filter 61 adjust.

Specifically, first, projecting a first wavelength filter 61 placed on the optical axis of the green laser light L _G, on the projection surface by reflecting the green laser beam L _G in the first wavelength filter 61 (virtual plane H1) To do. By adjusting the deflection angle and tilt angle of the first wavelength filter 61, the second projection point P2 of the green laser light L _G, close to the first projection point P1 of the red laser light L _R. As an example, using an imaging device such as CCD used for the adjustment of the red laser light L _R in the first step again, as the green laser beam L _G is incident on these CCD, the angle of the first wavelength filter 61 It is good to adjust. In addition, it is preferable that the second projection point P2 coincides with the first projection point P1. At this time, by adjusting the deflection angle of the first wavelength filter 61, the vertical position of the second projection point P2 (the position in the normal direction of the main surface 30a) changes, and the tilt angle of the first wavelength filter 61 is adjusted. As a result, the left-right position (the position in the direction along the main surface 30a and the virtual plane H1) varies. During the adjustment of the first color filter 61, a first position of the projection point P1 of the red laser light L _R also vary, red laser light L _R and the green laser beam L _G respective projection points P1, P2 coincide There is always a deflection angle and a tilt angle. After the above steps, the ultraviolet curable resin on the fourth sub-base member 54 is cured, and the first wavelength filter 61 is fixed to the fourth sub-base member 54.

Subsequently, as shown in FIG. 6, the second wavelength filter 62 is mounted on the main surface 30a of the base member 30 (fifth step). In this case, (as is preferably substantially coincides) a third projection point P3 of the blue laser beam L _B is as closer to the first projection point P1 of the red laser light L _R, the angle of the second wavelength filter 62 adjust. The second wavelength filter 62 is arranged so that the light reflection surface of the first wavelength filter 61 and the light reflection surface of the second wavelength filter 62 are parallel to each other. The specific adjustment method is the same as that in the fourth step described above.

  The effects obtained by the optical assembly 10A of the present embodiment described above and the manufacturing method thereof will be described. Generally, when the wavelength of laser light is different, the refractive index of the lens is also different. Therefore, when the laser light emitted from the red LD, green LD, and blue LD is collimated with one lens, chromatic aberration is generated, and it becomes difficult to align the optical axes of the laser lights. On the other hand, chromatic aberration can be effectively suppressed by arranging the three collimating lenses 41 to 43 corresponding to the red LD 11, the green LD 12, and the blue LD 13 as in the present embodiment.

  On the other hand, the optical assembly is often required to be downsized. If the entire optical assembly is reduced in size while arranging a collimating lens for each LD, the collimating lenses come close to each other, and a resin for fixing the collimating lens (in this embodiment, an ultraviolet curable resin is used) is another collimating lens. It flows out to the fixed position of the lens, which causes the optical axis of other collimating lenses to fluctuate. As a result, the optical axes of the laser beams are shifted from each other.

In view of the above-described problems, in the optical assembly 10A of the present embodiment, the collimating lenses 41 to 43 are disposed for the three color LDs 11 to 13, respectively. And these collimating lenses 41-43 are mounted on the main surface 30a of the base member 30 via the three sub base members 51-53 independent of each other. According to such a configuration, it is possible to effectively prevent the resin for fixing the collimating lenses 41 to 43 from flowing out to the fixing position of the other collimating lenses 41 to 43. Accordingly, it is possible to suppress optical axis fluctuations of the red laser beam L _R , the green laser beam L _G , and the blue laser beam L _B emitted from the LDs 11 to 13 and perform the optical axis adjustment with higher accuracy. Further, the optical assembly 10A can be downsized.

  In the configuration described in Patent Document 3, since parallelization is performed using one lens after the three colors of laser beams are combined, correction of chromatic aberration is virtually impossible. Further, in the configuration described in Patent Document 4, collimating lenses are provided in each of the three LDs, but these collimating lenses are housed in the lens holder, and the adjustment margin of the optical axis is extremely limited. . According to the optical assembly 10A of the present embodiment, by having the above-described configuration, it is possible to correct chromatic aberration, and to sufficiently adjust the optical axis while ensuring a sufficient adjustment margin of the optical axis. It becomes possible.

In the method of manufacturing the optical assembly 10A of the present embodiment, the red LD 11 is first mounted on the base member 30 (first step), and then the green LD 12 so that the height of the projection point is the same as that of the red LD 11. And the blue LD 13 are mounted on the base member 30 (second and third steps), and the projection points of the green LD 12 and the blue LD 13 are made the projection points of the red LD 11 using the first wavelength filter 61 and the second wavelength filter 62. It is approaching (fourth and fifth steps). Such method, red LD 11, green LD 12, and blue LD13 each laser beam _L R emitted from the _respective, L G, the optical axis of the _{L B,} it is possible to accurately and easily adjusted to one another.

  In the present embodiment, in the third step, the position of the green LD 12 projection point (second projection point P2) and the position of the blue LD 13 projection point (third projection point P3) are substantially the same. The blue LD 13 is arranged so as to match. Thereby, the structure (refer FIG. 1) by which green LD12 and blue LD13 are arrange | positioned at the one side of the optical axis of red LD11 is suitably realizable. In this case, in the fifth step, the second wavelength filter 62 is preferably arranged so as to be parallel to the first wavelength filter 61.

(Second Embodiment)
Subsequently, an optical module including the optical assembly 10A according to the first embodiment will be described. FIG. 7 is a perspective view showing an appearance of the optical module 1A according to the second embodiment. FIG. 8 is a perspective view showing the internal configuration by removing the cap 73 of the optical module 1A shown in FIG. The optical module 1A according to the present embodiment has a so-called coaxial CAN package.

The optical module 1A includes a stem 72, a cap 73, a condenser lens 74, and lead pins 75a to 75d in addition to the optical assembly 10A. The cap 73 holds the condenser lens 74. The condensing lens 74 is above the main surface 72a of the stem 72 and on the optical axis of the combined light of the laser beams L _R , L _G , and L _B (see FIG. 1) emitted from the optical assembly 10A. Has been placed. The main surface 72a has a diameter of 5.6 mm, for example. The lead pins 75 a to 75 d protrude on the main surface 72 a of the stem 72. The lead pins 75 a to 75 c are electrically insulated from the stem 72, and the lead pin 75 d is electrically connected to the stem 72.

  The base member 30 of the optical assembly 10 </ b> A is fixed on the main surface 72 a of the stem 72, and the main surface 30 a of the base member 30 extends perpendicular to the main surface 72 a of the stem 72. The optical assembly 10 </ b> A is hermetically sealed by the stem 72 and the cap 73. Each of the red LD11, green LD12, and blue LD13 electrodes of the optical assembly 10A is electrically connected to lead pins 75a to 75c via wires (not shown). The other electrodes of the red LD 11, green LD 12, and blue LD 13 are electrically connected to the lead pin 75 d via the stem 72.

The optical module 1A according to the present embodiment includes an optical assembly 10A. Therefore, the optical axes of the laser beams L _R , L _G , and L _B (see FIG. 1) emitted from the red LD 11, the green LD 12, and the blue LD 13 can be adjusted with high accuracy. In addition, the optical module 1A can be downsized.

(Third embodiment)
FIG. 9 is a perspective view showing an appearance of the optical module 1B according to the third embodiment. FIG. 10 is a perspective view showing the internal configuration by removing the glass cap 83 of the optical module 1B shown in FIG. FIG. 11A is a top view of the optical module 1B, and FIG. 11B is a side view of the optical module 1B.

  The optical module 1B includes a ceramic substrate 82 and a glass cap 83 in addition to the optical assembly 10A of the first embodiment. The ceramic substrate 82 is a plate-like member made of ceramic (for example, AlN or SiC) having a thickness of about 1 mm, for example, and can also serve as the base member 30 of the optical assembly 10A. The ceramic substrate 82 has a main surface 82a (corresponding to the main surface 30a of the base member 30). The LD 11-13, the collimating lenses 41-43, the wavelength filters 61, 62, etc. of the optical assembly 10A are the ceramic substrate 82. It is mounted on the main surface 82a. 9 to 11, the sub base members 51 to 55 are not shown.

A plurality of electrodes 84 a to 84 d are provided on the main surface 82 a of the ceramic substrate 82. These electrodes 84a to 84d are electrically connected to the respective LDs 11 to 13 through wirings not shown. In one example, the main surface 82a of the ceramic substrate 82 is a rectangular shape having a long side of 5.5 mm and a short side of 3.5 mm, and 2 mm of the longitudinal dimension is an area for disposing the electrodes 84a to 84d. The optical assembly 10A is disposed in the remaining 3.5 mm. The glass cap 83 has a thickness of 1 mm, for example, and is disposed on the main surface 82a to cover the optical assembly 10A. In addition, it may replace with the glass cap 83 and the cap which consists of opaque materials, such as a ceramic, may be arrange | positioned, and the reliability of the optical module 1B can further be improved. In that case, a transparent material may be provided in a portion through which the combined light of the laser beams L _R , L _G , and L _B (see FIG. 1) passes.

The optical module 1B according to this embodiment includes an optical assembly 10A. Therefore, the optical axes of the laser beams L _R , L _G , and L _B (see FIG. 1) emitted from the red LD 11, the green LD 12, and the blue LD 13 can be adjusted with high accuracy. Further, the optical module 1B can be downsized.

(Fourth embodiment)
FIG. 12 is a perspective view showing a configuration of an optical assembly 10B as the fourth embodiment. The optical assembly 10B of the present embodiment includes a reflecting member 90 in addition to the configuration of the optical assembly 10A of the first embodiment. In addition, since it is the same as that of 1st Embodiment regarding other structures except the reflection member 90, detailed description is abbreviate | omitted.

Reflecting member 90 is mounted on the main surface 30a of the base member 30, the laser light _L R, _{L G,} and is disposed on the optical axis of the combined light _{L B.} Reflecting member 90 has a light reflecting surface 90a, and reflects the laser beam _L R, _{L G,} and a combined light _{L B.} In one example, the light reflecting surface 90a forms an angle of 45 ° with respect to the optical axis of the combined light and the main surface 30a, and reflects the combined light along the normal direction of the main surface 30a.

FIG. 13 is a diagram illustrating a configuration (optical module 1C) in which a reflecting member 90 is added to the optical assembly 10A of the third embodiment to form an optical assembly 10B. In FIG. 13, the glass cap 83 is not shown. In the present embodiment, the three-color laser beam L _{R of,} L _G, and combined light reaches the reflecting member 90 of L _B, when it is reflected along the normal direction of the principal surface 82a of the ceramic substrate 82, the The combined light passes through the glass cap 83 and is preferably emitted to the outside of the optical module 1C.

  FIG. 14 is a perspective view showing an appearance of another optical module 1D according to the present embodiment. FIG. 15 is a perspective view showing an internal configuration of a part (ceramic package 91) of the optical module 1D. The optical module 1D includes a ceramic package 91 and a condensing optical unit 92.

The ceramic package 91 accommodates the optical assembly 10B of this embodiment (see FIG. 12). The ceramic package 91 is an extremely small package having an outer dimension of 4.0 mm × 4.7 mm × 1.5 mm, for example, and is made of a ceramic material such as alumina. As shown in FIG. 15, the optical assembly 10 </ b> B is mounted on the inner bottom surface 91 a of the ceramic package 91. The inner bottom surface 91a corresponds to the main surface 30a of the base member 30 shown in FIG. Three-color laser beam L _R of generated in the optical assembly _10B, combined light L _G, and L _B, after being reflected at the reflecting member 90, are emitted along the normal direction of the inner bottom surface 91a. In addition, in FIG. 15, illustration of the sub base members 51-55 is abbreviate | omitted.

  The condensing optical unit 92 shown in FIG. 14 includes a metal holder 94 that holds a condensing lens. The holder 94 has a cylindrical shape extending along the optical axis of the combined light emitted from the optical assembly 10 </ b> B, and is fixed to the top plate 93 of the ceramic package 91. A metal cylindrical joint 95 is fixed to the holder 94. The joint 95 has a through hole for allowing the combined light to pass therethrough. Further, a cylindrical metal sleeve 96 is fixed to the joint 95. A ferrule (not shown) holding an optical fiber is disposed inside the metal sleeve 96. The metal sleeve 96 functions as a receptacle, and the distal end portion of the optical connector is inserted into the metal sleeve 96. By providing a scanning system on the other end side of the optical fiber extending from the optical connector, for example, an ultra-small head-mounted display can be suitably realized. Note that the optical module 1D may have a fixed fiber structure such as a so-called pigtail fiber instead of the receptacle.

The optical assembly 10B and the optical modules 1C and 1D according to the present embodiment include the configuration of the optical assembly 10A of the first embodiment. Therefore, the red LD 11, green LD 12, and blue LD13 each laser beam _L R emitted from the respective, _{L G,} and the optical axis of the _{L B,} it is possible to accurately adjust to each other. Further, the optical assembly 10B and the optical modules 1C and 1D can be reduced in size.

(Fifth embodiment)
FIG. 16 is a perspective view showing a configuration of an optical assembly 10C as the fifth embodiment. The difference between the optical assembly 10C of the present embodiment and the optical assembly 10A of the first embodiment is the direction of the green LD 12. That is, green LD12 and the second collimating lens 42 of the present embodiment is arranged on the opposite side of the blue LD13 across the optical axis of the red laser light L _R extending from the red LD11 linearly. For this reason, the direction of the first wavelength filter 61 of this embodiment is also different from that of the first embodiment, and both surfaces of the first wavelength filter 61 form an angle of 90 ° with respect to both surfaces of the second wavelength filter 62. Yes. Since the configuration other than the green LD 12 and the first wavelength filter 61 is the same as that of the first embodiment, detailed description thereof is omitted.

  FIG. 17 is a perspective view showing the configuration of the optical module 1E of the present embodiment. The optical module 1E has a configuration in which the optical assembly 10A of the optical module 1A (see FIG. 8) of the second embodiment is replaced with the optical assembly 10C of the present embodiment. The base member 30 of the optical assembly 10C is fixed on the main surface 72a of the stem 72, and the main surface 30a extends perpendicularly to the main surface 72a. The optical assembly 10C is hermetically sealed by a stem 72 and a cap 73 (see FIG. 7).

The optical assembly 10C can be manufactured by the same manufacturing method as the optical assembly 10A of the first embodiment except for the following points. That is, when manufacturing the optical assembly 10C of the present embodiment, in the third step of mounting the blue LD 13 and the third collimating lens 43 on the base member 30, as shown in FIG. The blue LD 13 and the third collimating lens 43 may be arranged so that the relative positional relationship between the point P2 and the third projection point P3 is a relationship that sandwiches the first projection point P1. Further, in the fifth step of mounting the second wavelength filter 62 on the base member 30, as shown in FIG. 19, the normal line of the light reflecting surface of the first wavelength filter 61 and the light of the second wavelength filter 62. The second wavelength filter 62 may be disposed so that the normal lines of the reflecting surfaces intersect each other. In particular, when the optical axis of the green laser light L _G and the optical axis of the blue laser light L _B are parallel to each other, and normal to the light reflecting surface of the first color filter 61, the light in the second wavelength filter 62 The second wavelength filter 62 may be arranged so that the normal line of the reflecting surface is perpendicular to each other.

In the optical assembly 10 </ b> C of the present embodiment, each of the collimating lenses 41 to 43 is arranged for each of the three color LDs 11 to 13 as in the first embodiment. And these collimating lenses 41-43 are mounted on the main surface 30a of the base member 30 via the three sub base members 51-53 independent of each other. With such a configuration, it is possible to effectively prevent the resin for fixing the collimating lenses 41 to 43 from flowing out to the fixing positions of the other collimating lenses 41 to 43. Accordingly, it is possible to suppress optical axis fluctuations of the red laser beam L _R , the green laser beam L _G , and the blue laser beam L _B emitted from the LDs 11 to 13 and perform the optical axis adjustment with higher accuracy. Further, the optical assembly 10C can be downsized.

  In the present embodiment, in the third step, the relative positional relationship between the projection point of the green LD 12 (second projection point P2) and the projection point of the blue LD 13 (third projection point P3) is that of the red LD 11. The blue LD 13 and the third collimating lens 43 are arranged so as to sandwich the projection point (first projection point P1). Thereby, the structure (refer FIG. 16) by which green LD12 and blue LD13 are arrange | positioned on both sides of the optical axis of red LD11 is suitably realizable.

  In the present embodiment, since the green LD 12 and the blue LD 13 are separated from each other on the right and left of the optical axis of the red LD 11 and arranged in a balanced manner, the eccentricity of the output position of the combined light with respect to the package can be suppressed.

  In the present embodiment, as shown in FIG. 18, the position of the alignment mirror 70 used in the third step is the second step (see FIG. 3) across the optical axis of the red LD 11. ) On the opposite side of the position of the alignment mirror 70 in FIG. For this reason, it is necessary to prepare two alignment mirrors 70. Further, regarding the collet that holds the second wavelength filter 62, since the angle of the second wavelength filter 62 is different from that of the first wavelength filter 61, two types of collets having different angles are required. On the other hand, if the green LD 12 and the blue LD 13 are arranged on one side of the optical axis of the red LD 11 as in the first embodiment, one alignment mirror 70 is commonly used in the second and third steps. The number of alignment mirrors can be reduced, and the alignment accuracy between the green LD 12 and the blue LD 13 is improved. Furthermore, regarding the collet that holds the first wavelength filter 61 and the second wavelength filter 62, one collet can be used in common, and the manufacturing equipment can be simplified.

(Sixth embodiment)
FIG. 20 is a perspective view showing a configuration of an optical assembly 10D as the sixth embodiment. The optical assembly 10D of this embodiment includes a reflecting member 90 in addition to the configuration of the optical assembly 10C of the fifth embodiment. In addition, since it is the same as that of 1st Embodiment regarding other structures except the reflection member 90, detailed description is abbreviate | omitted.

Reflecting member 90 is mounted on the main surface 30a of the base member 30, the laser light _L R, _{L G,} and is disposed on the optical axis of the combined light _{L B.} Reflecting member 90 has a light reflecting surface 90a, and reflects the laser beam _L R, _{L G,} and a combined light _{L B.} In one example, the light reflecting surface 90a forms an angle of 45 ° with respect to the optical axis of the combined light and the main surface 30a, and reflects the combined light along the normal direction of the main surface 30a.

The optical assembly 10D according to the present embodiment includes the configuration of the optical assembly 10C of the fifth embodiment. Therefore, the red LD 11, green LD 12, and blue LD13 each laser beam _L R emitted from the respective, _{L G,} and the optical axis of the _{L B,} it is possible to accurately adjust to each other. Further, the optical assembly 10B and the optical modules 1C and 1D can be reduced in size.

(Seventh embodiment)
FIG. 21 is a perspective view showing a configuration of an optical assembly 10E as the seventh embodiment. The optical assembly 10E of this embodiment includes a first wavelength filter 63 and a second wavelength filter 64 instead of the first wavelength filter 61 and the second wavelength filter 62 of the first embodiment. In addition, the optical assembly 10E of the present embodiment includes a reflecting member 90.

The first wavelength filter 63 is a multilayer filter formed on a glass substrate, for example, and is mounted on the main surface 30 a of the base member 30 via the fourth sub-base member 54. One surface of the first wavelength filter 63 is optically coupled to the first collimating lens 41, and the other surface of the first wavelength filter 63 is optically coupled to the second collimating lens 42. The first wavelength filter 63 reflects the red laser light L _R collimated by the first collimator lens 41, passes through the green laser light L _G, which is collimated by the second collimating lens 42. And the optical axis of the red laser light L _R reflected at the first wavelength filter 63 and the optical axis of the green laser light L _G that has passed through the first color filter 63 are adjusted so as to substantially coincide with each other.

The second wavelength filter 64 is a multilayer filter formed on, for example, a glass substrate, and is mounted on the main surface 30 a of the base member 30 via the fifth sub-base member 55. One surface of the second wavelength filter 64 is optically coupled to the other surface of the first wavelength filter 63, and the other surface of the second wavelength filter 64 is optically coupled to the third collimating lens 43. Are combined. The second wavelength filter 64, a red laser beam has reached the first wavelength filter 63 L _R and green laser light L _{G (i.e.,} red laser light L _R is collimated by the first collimating lens _41, and the second collimating lens 42 The green laser beam L _G ) collimated by the above is reflected, and the laser beam L _B collimated by the third collimating lens 43 is transmitted. The optical axis of the reflected red laser beam L _R and the green laser beam L _G in the second wavelength filter 64 and the optical axis of the blue laser beam L _B having the second wavelength filter 64, tuned to substantially coincide with each other Has been.

Reflecting member 90 is mounted on the main surface 30a of the base member 30, the laser light _L R, _{L G,} and is disposed on the optical axis of the combined light _{L B.} Reflecting member 90 has a light reflecting surface 90a, and reflects the laser beam _L R, _{L G,} and a combined light _{L B.} In one example, the light reflecting surface 90a forms an angle of 45 ° with respect to the optical axis of the combined light and the main surface 30a, and reflects the combined light along the normal direction of the main surface 30a. Here, the reflecting member 90 shown in FIGS. 12, 13, and 20 has been described on the assumption that the reflecting surface 90a is uniform. That is, the case where the entire surface 90a that makes an angle of substantially 45 ° with respect to the main surface 30a has a light reflecting function has been described. As a modification, as shown in FIG. 21, a reflection region 90b in which only a part of the surface 90a is provided with a reflection function can be used.

  In the optical assembly according to the embodiment, the lights of the LDs 11 to 13 are propagated after being converted into substantial collimated light by the collimating lenses 41 to 43, respectively. The reflection region 90b is formed with a diameter smaller than the diameter of the collimated light, and the reflection region 90b is formed so that the shape of the reflection region 90b projected onto the main surface 30a is circular, thereby combining the reflected light. It becomes possible to make the shape of light circular. The visible LDs of the LDs 11 to 13 generally have a so-called ridge structure. The output light field pattern of the ridge type LD is an ellipse. This elliptical field pattern is maintained even when it passes through the collimating lens. As in the present example, the field pattern of the output light of the optical assembly 10 can be converted into a circle by making the shape of the reflection region 90b projected onto the main surface 30a into a circle.

In the optical assembly 10E of this embodiment, each of the collimating lenses 41 to 43 is arranged for each of the three color LDs 11 to 13, as in the first embodiment. And these collimating lenses 41-43 are mounted on the main surface 30a of the base member 30 via the three sub base members 51-53 independent of each other. With such a configuration, fluctuations in the optical axes of the red laser light L _R , the green laser light L _G , and the blue laser light L _B emitted from the LDs 11 to 13 can be suppressed, and the optical axis can be adjusted more accurately. It becomes. Further, the optical assembly 10E can be downsized.

Further, in the present embodiment, unlike the first embodiment, the first wavelength filter 63 reflects the red laser light L _R, and transmits green laser light L _G. In this case, it corresponds to the second laser beam of the red laser light L _R is invention emitted from the red LD 11, the green laser light L _G emitted from the green LD12 is equivalent to a first laser beam of the present invention . In the present embodiment, the second wavelength filter 64 reflects the light from the red LD 11 and the green LD 12 and transmits the light from the blue LD 13. That is, the second wavelength filter of the present invention performs one of the transmitted and reflected against the (red laser light L _R and the green laser beam L _G in the present _embodiment) light from the first wavelength filter 63, first The other of transmission and reflection may be performed on the laser beam 3 (blue laser beam L _{B in the} present embodiment).

(Eighth embodiment)
FIG. 22 is a top view showing the configuration of the optical assembly 10F as the eighth embodiment. For ease of understanding, the base member 30, the submounts 21 to 23, and the sub base members 51 to 55 are not shown in FIG.

  As shown in FIG. 22, the optical assembly 10F of the present embodiment further includes a red LD 14, a green LD 15, and a blue LD 16 in addition to the configuration of the first embodiment. The optical assembly 10F further includes three λ / 2 plates 24 to 26, three polarization filters 34 to 36, and three collimating lenses 44 to 46.

The red LD 14 is the fourth LD in the present embodiment, and laser light (fourth laser light) included in the red wavelength range (first wavelength range) among the three wavelength ranges of red, green, and blue. ) _Emit LR2. The red LD 14 is mounted on a submount (not shown) different from the red LD11, and is mounted on the main surface 30a of the base member 30 via the submount. Red LD14 emits a red laser beam _{L R2} with the optical axis along the main surface 30a. In the present embodiment, the emission direction of the red laser light L _R2 from the red LD14 intersects with respect to the emission direction of the red laser light L _R from the red LD 11. Wavelength of the red laser light _{L R2} is, for example, the same 640nm red laser beam _{L R} of the red LD 11.

Green LD15 is a fifth LD in this embodiment emits the L _G2 laser light contained in the green wavelength band (second wavelength range) (laser light of the 5) among the three wavelength bands . The green LD 15 is mounted on a submount (not shown) different from the green LD 12, and is mounted on the main surface 30a of the base member 30 via the submount. Green LD15 emits green laser light _{L G2} with the optical axis along the main surface 30a. In the present embodiment, the direction of emission of the green laser beam L _G2 from the green LD15 intersects with respect to the emission direction of the green laser light L _G from the green LD 12. Wavelength of the green laser beam _{L G2} is, for example, the same 535nm green laser beam _{L G} of the green LD 12.

The blue LD 16 is the sixth LD in the present embodiment, and emits a laser beam (sixth laser beam) L _B2 included in the blue wavelength region (third wavelength region) among the three wavelength regions. . The blue LD 16 is mounted on a submount (not shown) different from the blue LD 13 and is mounted on the main surface 30a of the base member 30 via the submount. The blue LD 16 emits the blue laser beam L _B2 along the optical axis along the main surface 30a. In the present embodiment, the direction of emission of the blue laser beam L _B2 from the blue LD16 intersects with respect to the emission direction of the blue laser light L _B from the blue LD 13. Wavelength of the blue laser beam _{L B2} is, for example, the same 440nm blue laser beam _{L B} of the blue LD 13.

Each of the collimating lenses 44 to 46 is optically coupled to each light emitting end face of each of the red LD 14, the green LD 15, and the blue LD 16. Each of the collimating lenses 44 to 46 collimates (collimates) the red laser light L _R2 , the green laser light L _G2 , and the blue laser light L _B2 emitted from the red LD 14, the green LD 15, and the blue LD 16, respectively. The collimating lenses 44 to 46 are mounted on a sub-base member (not shown), and are mounted on the main surface 30a of the base member 30 via the sub-base member.

The λ / 2 plate 24 is the first λ / 2 plate in the present embodiment, is optically coupled to the collimating lens 44, and transmits the red laser light _LR2 . At this time, the plane of polarization of the red laser light _{L R2} is rotated 90 °. The λ / 2 plate 25 is the second λ / 2 plate in the present embodiment, is optically coupled to the collimating lens 45, and transmits the green laser light _LG2 . At this time, the plane of polarization of the green laser light _{L G2} is rotated 90 °. The λ / 2 plate 26 is the third λ / 2 plate in the present embodiment, is optically coupled to the collimating lens 46, and transmits the blue laser light _LB2 . At this time, the polarization plane of the blue laser light L _B2 is rotated by 90 °.

  For example, the polarization filters 34 to 36 have high transmittance and low reflectance for polarized light in one plane, and low transmittance and high reflectance for polarized light in another plane perpendicular to the plane. It is a filter having optical characteristics.

The polarization filter 34 is the first polarization filter in the present embodiment, and one surface thereof is optically coupled to the collimator lens 41, and the other surface is optically coupled to the λ / 2 plate 24. Is bound to. Polarization filter 34 includes a red laser light L _R2 transmitted through the lambda / 2 plate 24, by passing through the red laser light L _R Tonouchi one laser beam, and reflects the other laser beam, these lasers Polarization synthesis of the light beams L _R and L _R2 is performed.

The polarization filter 35 is the second polarization filter in the present embodiment, and one surface thereof is optically coupled to the collimator lens 42, and the other surface is optically coupled to the λ / 2 plate 25. Is bound to. Polarization filter 35, by reflecting the green laser beam L _G2 passing through the lambda / 2 plate 25, transmitted through the green laser light L _G Tonouchi one laser beam, the other laser beam, these lasers Polarization synthesis of the light L _G and L _G2 is performed.

The polarization filter 36 is the third polarization filter in the present embodiment, and one surface thereof is optically coupled to the collimator lens 43, and the other surface is optically coupled to the λ / 2 plate 26. Is bound to. Polarization filter 36, the blue laser beam L _B2 transmitted through the lambda / 2 plate 26, by passing through the blue laser light L _B Tonouchi one laser beam, and reflects the other laser beam, these lasers Polarization synthesis of the light L _B and L _B2 is performed.

The first wavelength filter 61 transmits the combined light (first combined light) output from the polarization filter 34, that is, the combined light composed of the red laser beams _LR and _LR2, and is output from the polarization filter 35. combined light (the second coupled lights), i.e. it reflects the combined light made from the green laser light L _G and L _G2. The optical axis of the synthesized light transmitted through the first wavelength filter 61 and the optical axis of the synthesized light reflected by the first wavelength filter 61 are adjusted so as to substantially coincide with each other.

The second wavelength filter 62 transmits the combined light reaching the first wavelength filter 61 and is composed of the combined light (third combined light) output from the polarization filter 36, that is, the blue laser beams L _B and L _B2. Reflects the combined light. The optical axis of the synthesized light transmitted through the second wavelength filter 62 and the optical axis of the synthesized light reflected by the second wavelength filter 62 are adjusted so as to substantially coincide with each other.

The optical assembly 10F of this embodiment will be described in detail. At present, surface-emitting types are not realized as blue LD and green LD, and these LDs are end-emitting types. When the red LDs 11 and 14, the green LDs 12 and 15, and the blue LDs 13 and 16 are edge-emitting LDs, and the stacking direction of the semiconductor layers is perpendicular to the main surface 30 a of the base member 30, these LDs 11 to 16 The polarization planes of the emitted laser beams L _R , L _G , L _B , L _R2 , L _G2 , and L _B2 are all in a plane parallel to the main surface 30a (formed by the optical axis of the laser beam of each color). In the virtual plane). In this optical assembly 10F, the polarization plane of one of the red laser beams L _R and L _R2 (in this embodiment, the laser beam L _R2 ) is rotated by 90 ° by the λ / 2 plate 24, and then these red laser beams L Polarization synthesis of _{R 1} and L _R2 is performed. As a result, it is possible to output red laser light having the light intensity of two LDs. The same applies to the green laser beams L _G and L _G2 and the blue laser beams L _B and L _B2 . Therefore, according to the optical assembly 10F of the present embodiment, the red laser beam L _R2 , the green laser beam L _G2 , and the blue laser beam L _B2 having higher light intensity can be suitably combined and output. Such an optical assembly 10F is suitable, for example, for a projector or the like that requires a large amount of light, where one LD for each color has insufficient light amount.

  Further, in the optical assembly 10F of the present embodiment, each of the collimating lenses 41 to 46 is arranged for each of the three color LDs 11 to 16, as in the first embodiment. These collimating lenses 41 to 46 are mounted on the main surface 30a of the base member 30 via six sub-base members (not shown) that are independent from each other. With such a configuration, fluctuations in the optical axis of the laser light emitted from the LDs 11 to 16 can be suppressed, and the optical axis can be adjusted more accurately. Further, the optical assembly 10F can be downsized.

  In this embodiment, the λ / 2 plates 24 to 26 are required. However, since the λ / 2 plate is essentially a birefringent crystal plate, the size of the components is not greatly increased. Therefore, although the number of parts increases, each λ / 2 plate itself is much smaller than the case where the individual LD is sealed in the package as in the configuration described in the prior art. When two LDs are used for each color, the configuration described in the prior art requires as many as six packages. In this embodiment, each LD and λ / 2 plate are accommodated in one package. Can be significantly reduced in size.

(First modification)
FIG. 23 is a top view showing a configuration of an optical assembly 10G as a modification of the eighth embodiment. For ease of understanding, illustration of the base member 30, the submounts 21 to 23, and the sub base members 51 to 55 is also omitted in FIG. The optical assembly 10G of this modification has a configuration in which the red LD 14, the collimating lens 44, and the λ / 2 plate 24 are deleted from the configuration of the optical assembly 10F of the eighth embodiment.

  In this modification, only red laser light is generated from a single LD (red LD 11), and green laser light and blue laser light are respectively generated from two LDs (green LD 12 and 15, blue LD 13 and 16). Yes. For example, in consumer applications such as a head-mounted display, the monochromaticity (coherency) of laser light may not be required so much. On the contrary, if the coherency is too strong, it becomes weak against noise light, and an undesirable phenomenon such as an increase in flickering on the display may occur. Visual flickering is noticeable for light on the short wavelength side such as green light and blue light rather than red light. Therefore, in this modification, monochromaticity of the combined light is relaxed by using two LDs for green laser light and blue laser light and performing polarization combining. At present, only green LD and blue LD whose light output intensity is smaller than that of red LD are realized. Furthermore, when red laser light is combined with green laser light and blue laser light, the oscillation characteristics of the red LD may be impaired. Therefore, as in this modification, a plurality of LDs are used for green laser light and blue laser light with relatively low light output intensities, and red laser light is covered by a single LD. The balance of strength can be suitably maintained.

(Second modification)
In the above-described eighth embodiment, the center wavelengths of the red laser beam L _R2 of the red LD 14, the green laser beam L _G2 of the green LD 15, and the blue laser beam L _B2 of the blue LD 16 are set to the red laser beam L _R of the red LD 11, Although the center wavelengths of the green laser light L _G of the green LD 12 and the blue laser light L _B of the blue LD 13 are the same, the center wavelengths may be different from each other in order to reduce coherency. For example, the center wavelength of the red laser light _{L R} and (640 + α) nm, if the center wavelength of the red laser light _{L R2} and (640 + β) nm (where alpha ≠ beta), reducing the coherency of the red laser light after synthesis can do. Similarly, the center wavelength of the green laser light _{L G} and (530 + α) nm, the center wavelength of the green laser light _{L G2} and (530 + β) nm, the center wavelength of the blue laser light _{L B} and (440 + α) nm, blue laser If the center wavelength of the light L _B2 is (440 + β) nm, the coherency of the combined green laser light and blue laser light can be reduced.

  The method for manufacturing an optical assembly and the optical assembly according to the present invention are not limited to the above-described embodiments, and various other modifications are possible. For example, in the first embodiment, the first wavelength region of the three wavelength regions of red, green, and blue is the red wavelength region, the second wavelength region is the green wavelength region, and the third wavelength region is However, the combination of the first to third wavelength ranges, the red wavelength range, the green wavelength range, and the blue wavelength range is not limited to this, and various combinations can be applied. The first to third laser diodes are combined with red LD, green LD, and blue LD, and the first to third laser beams are combined with red laser light, green laser light, and blue laser light. It is the same.

DESCRIPTION OF SYMBOLS 1A-1E ... Optical module, 10A-10G ... Optical assembly, 11, 14 ... Red LD, 12, 15 ... Green LD, 13, 16 ... Blue LD, 21 ... 1st submount, 22 ... 2nd submount, 23 3rd submount, 24 ... 1st λ / 2 plate, 25 ... 2nd λ / 2 plate, 26 ... 3rd λ / 2 plate, 30 ... Base member, 30a ... Main surface, 34 ... 1st Polarization filter, 35 ... second polarization filter, 36 ... third polarization filter, 41 ... first collimating lens, 42 ... second collimating lens, 43 ... third collimating lens, 44-46 ... collimating lens , 51 ... 1st sub base member, 52 ... 2nd sub base member, 53 ... 3rd sub base member, 54 ... 4th sub base member, 55 ... 5th sub base member, 61 ... 1st wavelength filter, 62 ... Second wavelength filter, 70... Mirror for core, 72 ... Stem, 73 ... Cap, 74 ... Condensing lens, 75a to 75d ... Lead pin, 82 ... Ceramic substrate, 83 ... Glass cap, 90 ... Reflective member, 91 ... Ceramic package, 92 ... Condensing optical part , 93 ... Top plate, 94 ... Holder, 95 ... Joint, 96 ... Metal sleeve, H1 ... Virtual plane, L _B , L _B2 ... Blue laser light, L _G , L _G2 ... Green laser light, L _R , L _R2 ... Red laser light, P1 ... first projection point, P2 ... second projection point, P3 ... third projection point.

Claims (5)

A method of manufacturing an optical assembly that combines and outputs red, green, and blue laser beams,
The first laser beam that emits the first laser beam is projected so that the first laser beam included in the first wavelength region of the three wavelength regions of red, green, and blue is projected onto the first projection point. A first step of mounting one laser diode on the main surface of the base member;
The second laser light included in the second wavelength region of the three wavelength regions has a second height that is the same as the first projection point with respect to the main surface of the base member. A second step of mounting a second laser diode that emits the second laser light on the main surface of the base member so as to be projected onto a projection point;
The height of the third laser light included in the third wavelength region of the three wavelength regions with respect to the main surface of the base member is the same as that of the first and second projection points. A third step of mounting a third laser diode that emits the third laser light on the main surface of the base member so as to be projected onto a third projection point;
Before or after the third step, a first wavelength filter that transmits the first laser beam and reflects the second laser beam is used, and the second projection point is the first projection point. A fourth step of mounting on the main surface of the base member so as to approach,
A second wavelength filter that transmits the first and second laser beams and reflects the third laser beam is arranged so that the third projection point approaches the first projection point. And a fifth step of mounting on the main surface.   2. The method of manufacturing an optical assembly according to claim 1, wherein in the third step, the third laser diode is arranged so that positions of the second and third projection points substantially coincide with each other.   3. The method of manufacturing an optical assembly according to claim 2, wherein, in the fifth step, the first and second wavelength filters are arranged so as to be parallel to each other.   2. The third laser diode according to claim 1, wherein, in the third step, the third laser diode is arranged so that a relative positional relationship between the second and third projection points is a relationship sandwiching the first projection point. Manufacturing method of optical assembly.   5. The method of manufacturing an optical assembly according to claim 4, wherein, in the fifth step, the first and second wavelength filters are arranged so as to be perpendicular to each other.

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