JP2006196505A - Semiconductor laser device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor laser device whose center axis of a laser beam becomes precisely vertical to a main face of a stem of a package when a semiconductor laser chip whose center axis of the laser beam is inclined to a substrate-side is assembled into the package by a junction down system suitable for a high output operation. <P>SOLUTION: An inclined face 51 is installed on a sub-mount 5 loading the semiconductor laser chip 1 so that width in a direction parallel to the stem main face 25 is reduced as it is detached from the stem 9 in a cross-sectional shape. The semiconductor laser chip 1 is arranged on the fixed face 4 of the inclined face 51. The fixed face 4 is inclined in a direction where an angle α1 which the extension face 23 of the fixed face 4 and the stem main face 25 makes, and which is viewed from the side of sub-mount 5 becomes smaller than 90°. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a semiconductor laser device (hereinafter referred to as a semiconductor laser) used for a light source or the like of an optical information processing apparatus, and particularly in a package for installing and storing the semiconductor laser chip (hereinafter referred to as a laser chip). A semiconductor laser capable of reducing the inclination of the central axis of the laser light emitted from the laser chip (the central axis of the light intensity distribution in the far-field image; hereinafter referred to as the laser optical axis) in the direction perpendicular to the package main surface. The present invention relates to an assembly structure.

  In an assembly structure used in a conventional semiconductor laser package, the shape of assembly members such as a submount on which a laser chip is mounted and a heat sink is a rectangular parallelepiped (including a cube, the same applies hereinafter), and adjacent constituent surfaces are mutually Because of the right angle, the surface on which the laser chip is installed is perpendicular to the package main surface.

  Therefore, when a laser chip whose laser optical axis is inclined from the vertical direction of the laser resonator end face is assembled on the package stem by the assembly member, there is a problem that the laser optical axis is also inclined from the vertical direction of the package main surface. It was.

  When a semiconductor laser having such a laser optical axis tilted from the package main surface is used as a light source such as an optical pickup of an optical disk writing device, the optical coupling efficiency between the semiconductor laser and the optical system is deteriorated, and a DVD (Digital Versatile Disk) is obtained. In applications where high output operation such as for optical disk writing is indispensable, there is a problem that a sufficiently high light density necessary for writing cannot be stably obtained on the disk surface, and a writing error occurs. .

  On the other hand, the laser chip mounting surface of the heat sink is cut obliquely in a semiconductor laser with a conventional junction-up assembly structure in which the active layer side surface of the laser chip is separated from the heat sink and the substrate side is fixed to the heat sink. A can package that compensates for the inclination of the optical axis of the laser beam by making the angle seen from the heat sink side formed by the extension surface of the fixing surface of the laser chip and the heat sink and the main surface of the stem larger than 90 °. The structure is known (see, for example, Patent Document 1).

Japanese Laid-Open Patent Publication No. 1-138781 (page 3, FIGS. 1 and 4)

  In the above conventional semiconductor laser assembly structure, the angle of the heat sink side formed by the extension surface of the fixing surface of the laser chip and the heat sink and the main surface of the stem is larger than 90 °, so the laser optical axis is laser resonant. When a laser chip tilted closer to the substrate with respect to the vertical direction of the end face of the device is applied to a semiconductor laser using a junction-down assembly structure in which the laser chip surface close to the active layer is fixed to a heat sink, the laser optical axis There arises a problem that the inclination of the stem main surface with respect to the perpendicular is further increased.

  The present invention has been made to solve the above problems, and can be applied to a semiconductor laser having a junction-down assembly structure with good heat dissipation suitable for a high-power semiconductor laser driven with a large current and generating a large amount of heat. An object of the present invention is to realize an assembly structure of a semiconductor laser having a laser optical axis that is exactly perpendicular to the stem main surface of the can package.

  Further, the second object of the present invention is that the conventional assembling apparatus and process can be used as they are, and any of junction up or junction down can be performed without causing a large increase in assembly cost due to a change in assembly members or the like. The assembling method is also intended to realize a semiconductor laser assembling structure capable of realizing a laser beam perpendicular to a stem main surface which is an optical reference surface.

  In the semiconductor laser according to the present invention, the laser chip whose laser optical axis is inclined toward the substrate side with respect to the perpendicular to the end face of the laser resonator and the laser chip mounting structure to which the active layer side surface is fixed are packaged. The laser formed by the stem main surface and the extension surface of the fixing surface to which the laser chip and the laser chip mounting structure are fixed so that the laser optical axis is perpendicular to the main surface of the stem when installed on the stem The fixing surface is inclined in a direction in which the angle viewed from the chip mounting structure side is smaller than 90 °.

  The present invention is a so-called laser chip in which the laser optical axis emitted from the active layer is inclined to the substrate side with respect to the perpendicular to the end face of the laser resonator, and the surface on the active layer side is fixed to the laser chip mounting structure. When assembled in a junction-down configuration, the tilt of the laser optical axis is compensated by the structure of the laser chip mounting structure and the stem, and the laser optical axis is relative to the main surface of the stem, which is the optical reference surface of the package, or the lower surface. And a vertical semiconductor laser can be realized accurately.

  In an embodiment for carrying out the present invention, a 660 nm band high-power semiconductor laser for optical disk writing (hereinafter referred to as a high-power laser) using an AlGaInP-based material will be described.

Embodiment 1 FIG.
FIG. 1A is a perspective view of a semiconductor laser assembled on a stem of a can package (a sealing cap is not shown) according to Embodiment 1 for carrying out the present invention. FIG. 2B is a cross-sectional view of the semiconductor laser of FIG. 1A taken along the AA plane perpendicular to the stem main surface 25, including the laser chip 1, the submount 5, and the heat sink 7a. In the drawings, the same reference numeral indicates the same component.

  In the semiconductor laser according to the first embodiment shown in FIG. 1, a laser chip mounting structure (hereinafter referred to as a chip mounting structure) includes a submount 5 and a heat sink 7a on which the submount 5 is mounted. The mount 5 has an inclined surface 51 whose width in the direction parallel to the stem main surface 25 decreases as the distance from the stem 9 increases in the cross section perpendicular to the active layer 3 of the laser chip 1 and including the laser optical axis 21. The laser chip 1 is fixed and installed such that the surface on the active layer 3 side is in contact with the fixing surface 4 forming a part on the inclined surface 51.

In addition, the shape of the submount 5 is a rectangular parallelepiped (including a cube, the same applies hereinafter), and the submount 5 is fixedly attached to the heat sink 7a on the installation surface 6 forming a part on the heat sink 7a.
The heat sink 7a has a rectangular parallelepiped shape, and the laser light emission direction is substantially perpendicular to the stem main surface 25, that is, above the stem 9, so that the upper surface of the stem main surface 25 is The installation surface 8 is fixedly installed on the stem main surface 25.

  Here, the laser chip 1 includes an active layer 3 formed of, for example, a double heterostructure made of AlGaInP (aluminum / gallium / indium / phosphorus) based material on a GaAs substrate (hereinafter referred to as substrate) 2 which is a semiconductor substrate. In addition, electrodes (not shown in FIG. 1) made of a metal thin film and gold plating are formed on the surface of the laser chip 1 on the substrate 2 side and on the surface of the active layer 3 side, respectively.

  In addition, as a material of the heat sink 7a, it is necessary to use a material having as good a thermal conductivity as possible and easy to process, for example, silver (Ag), copper (Cu), iron (Fe), aluminum (Al). At least one of them can be used.

  The laser optical axis 21 emitted from the active layer 3 in the double hetero structure of the laser chip 1 is inclined toward the substrate 2 by an angle θ with respect to the normal 22 on the laser resonator end face 20. The angle θ depends on the internal structure of the laser chip, the material, the manufacturing process, and the like, but is about 0.5 ° to 5 ° in the case of the high-power laser according to the first embodiment.

  The cause of the inclination of the laser optical axis 21 is due to the asymmetry of the effective refractive index distribution in the semiconductor layers above and below the active layer 3. In many cases, the refractive index distribution is designed to be asymmetrical around the active layer by design (for example, “High-Power 980-nm Ridge Waveguide Laser Diodes Included An Asymmetrically Expanded Optical Element”). K. Shigihara et al., IEEE JOURNAL OF QUANTUM ELECTRONIS, VOL. 38, No. 8, PP. 1081 1088).

  1A and 1B, the laser chip 1 has a fixing surface 4 on the submount 5 of the chip mounting structure whose surface on the active layer 3 side includes the submount 5 and the heat sink 7a. In FIG. 5, the solder is fixed by a junction down method with a solder material such as AuSn (gold tin). Further, the submount 5 is fixed to a heat sink 7a made of a metal such as silver (Ag) using a solder material such as AuSn.

  Here, the shape of the submount 5 constituting the chip mounting structure is not a plate-shaped rectangular parallelepiped as in the prior art, but in a cross section perpendicular to the active layer 3 of the laser chip 1 and including the laser optical axis 21, the stem 9. The inclination main surface 25 has an inclined surface 51 whose width (thickness) decreases in a direction parallel to the stem main surface 25, and the inclination angle β with respect to the perpendicular of the stem main surface 25 is the inclination of the laser optical axis 21. The same value as the angle θ to be performed (β = θ). Since the laser chip 1 is fixed to the fixing surface 4 on the inclined surface 51, the entire laser chip 1 is effectively inclined counterclockwise.

Accordingly, the extension surface 23 of the fixing surface 4 of the laser chip 1 is also inclined to the heat sink 7a side by the same angle as the angle θ, and the angle α1 viewed from the heat sink 7a side formed by the extension surface 23 and the stem main surface 25 is 90. An angle smaller than °, that is, α1 = (90−θ) °.
As a result, as shown in FIG. 1 (b), the inclination of the laser resonator end face 20 of the laser optical axis 21 is apparently accurately seen when the center axis 21 of the laser light is relative to the stem main surface 25 when viewed from outside the package. Compensated to be in the vertical direction.

  Note that the angle θ at which the laser optical axis 21 is inclined is about 0.5 ° to 5 ° in the case of the high-power laser according to the first embodiment, and therefore the perpendicular between the inclined surface 51 and the stem main surface 25 is The formed angle β is also preferably 0.5 ° to 5 °. As the actual value of α1, for example, if the angle of inclination of the laser optical axis 21 is θ = 3 °, α1 = (90−θ) ° = 87 °.

  In actual high-power laser products, θ varies within a certain range for each element depending on the structural design parameters and the manufacturing process. Therefore, according to the center value of the variation, α1 (that is, the inclination angle of the submount) If β) is set, a semiconductor laser compensated so that the laser optical axis 21 is accurately perpendicular to the stem main surface 25 can be obtained with a high yield.

  As the material of the submount 5, for example, silicon (Si), aluminum nitride (AlN), silicon carbide (SiC), diamond (C) having a thermal expansion coefficient as close as possible to the substrate 2 and high thermal conductivity. ), And using at least one of copper tungsten (CuW), a semiconductor laser having good temperature characteristics and reliability and having the laser optical axis 21 perpendicular to the stem main surface 25 accurately. Can be realized.

  Further, as the material of the heat sink 7a, by using at least one material of silver (Ag), copper (Cu), iron (Fe), and aluminum (Al) that has high thermal conductivity and is easy to process, low It is possible to realize a semiconductor laser that has good temperature characteristics at a cost and in which the laser optical axis 21 is accurately perpendicular to the stem main surface 25.

  By realizing a semiconductor laser in which such a laser optical axis is accurately perpendicular to the main surface of the stem, the optical coupling efficiency between the semiconductor laser and the optical system can be increased in semiconductor laser application equipment. There is a merit that an optical pickup for writing optical discs and the like having low optical system stability and high reliability, that is, high reliability and manufacturing yield can be realized.

Embodiment 2. FIG.
FIG. 2 is a sectional view showing the structure of the semiconductor laser according to the second embodiment. In the second embodiment, parts that are the same as or equivalent to those in the first embodiment shown in FIGS. 1A and 1B are denoted by the same reference numerals, description thereof is omitted, and only different parts are described. .

  In the first embodiment, the submount 5 is provided with the inclined surface 51. However, in the second embodiment, as shown in FIG. 2, the submount 5 is a plate-shaped rectangular parallelepiped, and the heat sink 7b is a laser chip. In a cross section perpendicular to one active layer 3 and including the laser optical axis 21, an inclined surface 71 whose width in the direction parallel to the stem main surface 25 decreases as the distance from the stem increases. The submount 5 is installed on a part of the installation surface 6 on the inclined surface 71, and the laser chip 1 is installed so that the surface on the active layer 3 side is in contact with the fixing surface 4 on the surface of the submount 5. is there.

  Here, on the inclined surface 71 of the heat sink 7b, the inclination angle β is set to the same value (β = θ) as the inclination angle θ of the laser optical axis 21. Since the rectangular parallelepiped submount 5 is installed on a part of the installation surface 6 on the inclined surface, the laser chip 1 is effectively inclined counterclockwise as in the first embodiment. .

  As a result, the extension surface 23 of the fixing surface 4 of the laser chip 1 is also inclined to the heat sink 7b side by the same angle as θ, and the angle α1 viewed from the heat sink 7b side formed by the extension surface 23 and the stem main surface 25 is 90 °. A smaller angle, that is, α1 = 90−θ. As a result, as shown in FIG. 2, the tilt angle θ of the laser resonator 21 at the laser resonator end face 20 is apparently compensated when viewed from the outside of the package, and the laser optical axis 21 is accurately perpendicular to the stem main surface 25. Become.

In the case of the high-power laser according to the first embodiment, the inclination angle θ of the laser optical axis 21 is about 0.5 ° to 5 °, so that the perpendicular between the inclined surface 71 and the stem main surface 25 is formed. The angle β is also preferably 0.5 ° to 5 °. As the actual value of α1, for example, if the angle of inclination of the laser optical axis 21 is θ = 3 °, α1 = (90−θ) ° = 87 °.

  In the first embodiment, since the submount 5 is made of a hard material such as ceramic such as AlN (aluminum nitride) or silicon and difficult to process, it takes cost to form the inclined surface. According to the second embodiment, since the heat sink 7b is made of a metal such as silver, copper, or iron that is easy to process, the inclined surface 71 is formed by an inexpensive method suitable for mass production, such as a shaping method using a mold. Therefore, there is an advantage that a semiconductor laser in which the laser optical axis 21 is perpendicular to the stem main surface 25 can be realized at low cost.

Embodiment 3 FIG.
FIG. 3 is a sectional view showing the structure of the semiconductor laser according to the third embodiment. In the third embodiment, parts that are the same as or equivalent to those in the first embodiment shown in FIGS. 1A and 1B are denoted by the same reference numerals, description thereof is omitted, and only different parts are described in detail. explain.

  In the second embodiment, the entire surface on the side where the submount 5 of the heat sink 7b is installed is the inclined surface. However, in the third embodiment, the cross section of the heat sink 7c, that is, the laser chip 1 In a cross section perpendicular to the active layer 3 and including the laser optical axis 21, an inclined surface 72 whose width in the direction parallel to the stem main surface 25 decreases as the distance from the stem 9 decreases, on the side where the submount 7 b is installed. It is formed in a partial region above the surface. The submount 5 in which the active layer 3 side surface of the laser chip 1 is fixed by the fixing surface 4 is installed on the installation surface 6 which is a part of the inclined surface 72.

  In the third embodiment, the inclination angle β of the inclined surface 72 of the heat sink 7c is set to the same angle as the inclination angle θ of the laser optical axis 21, and the submount 5 is a plate-shaped rectangular parallelepiped. Therefore, as can be seen from FIG. 3, the extension surface 23 of the fixing surface 4 on the submount 5 of the laser chip 1 is inclined to the heat sink 7c side by the same angle as θ, and is formed by the extension surface 23 and the stem main surface 25. The angle α1 viewed from the heat sink 7c side is smaller than 90 °, that is, α1 = (90−θ) °.

  Since the rectangular parallelepiped submount 5 on which the laser chip 1 is mounted is installed on the installation surface 6 on the inclined surface 72, the laser chip 1 is effectively counterclockwise as in the first and second embodiments. Will be inclined to. As a result, as shown in FIG. 3, the inclination of the laser resonator end face 20 of the laser optical axis 21 is apparently compensated when viewed from the outside of the package, so that the laser light is emitted in a direction perpendicular to the stem main surface 25 accurately. become.

  Note that the tilt angle θ of the laser optical axis 21 is about 0.5 ° to 5 ° in the case of the high-power laser according to the third embodiment, so that the perpendicular between the tilted surface 71 and the stem main surface 25 forms. The angle β may also be set to 0.5 ° to 5 °. Further, the actual value of α1 is, for example, α1 = (90−θ) ° = 87 ° when the inclination angle of the laser optical axis 21 is θ = 3 °.

  According to the third embodiment, a rectangular parallelepiped heat sink having an inclined shape 72 having various angles is obtained by a machining method such as mechanical polishing in accordance with the inclination angle θ of the laser optical axis of the laser chip. A heat sink can be easily manufactured. Accordingly, by selecting the inclination angle β of the inclined surface 72 corresponding to the center of distribution for each manufacturing lot of semiconductor lasers, compensation is made so that the laser optical axis 21 is accurately perpendicular to the stem main surface 25. There is an advantage that the manufactured semiconductor laser can be manufactured at low cost.

Embodiment 4 FIG.
FIG. 4 is a sectional view showing the structure of the semiconductor laser according to the fourth embodiment. In the fourth embodiment, the same or corresponding parts as those in the first embodiment of FIGS. 1A and 1B are denoted by the same reference numerals, description thereof is omitted, and only different parts are described. .

  In the second embodiment, the heat sink 7b is provided with the inclined surface 71, and in the third embodiment, the heat sink 7c is provided with the inclined surface 72, and the submount 5 is disposed on the inclined surface 71 or 72. In the fourth embodiment, as shown in FIG. 4, the heat sink 7 a is formed in a rectangular parallelepiped shape as in the first embodiment, and a wedge-shaped that forms a convex portion having an inclined surface 73 between the heat sink 7 a and the submount 5. The member 11d is provided, the submount 5 is installed on the inclined surface 73, and the laser chip 1 is fixed so that the surface on the active layer 3 side is in contact with the fixing surface 4 forming a part on the submount 5 It is.

  The wedge-shaped member 11 d having the inclined surface 73 is such that the width in the direction parallel to the stem main surface 25 decreases as the distance from the stem 9 increases in the cross section perpendicular to the active layer 3 of the laser chip 1 and including the laser optical axis 21. The inclination angle β of the inclined surface 73 is set to the same value as the angle θ at which the laser optical axis 21 is inclined.

  Therefore, as in the second and third embodiments, the extension surface 23 of the fixing surface 4 of the laser chip is inclined to the heat sink 7a side by the same angle as the inclination angle θ of the laser optical axis 21, and the extension surface 23 is The angle α1 viewed from the heat sink 7a side formed by the stem main surface 25 is an angle smaller than 90 °, that is, α1 = (90−θ) °. Thereby, similarly to the first to third embodiments, the laser optical axis 21 is compensated so as to be accurately perpendicular to the stem main surface 25.

  As described above, in the fourth embodiment, as a method of providing a convex portion having an inclined surface on a part of the heat sink 7a, a wedge-shaped member 11d is prepared and sandwiched between the heat sink 7a and the submount 5. It is fixed with. According to this method, by preparing a wedge-shaped member 11d having various inclination angles β, the laser optical axis 21 can be adapted to variations in the inclination angle θ of the laser optical axis 21 in each laser chip 1. Can be compensated so as to be more accurately perpendicular to the stem main surface 25.

  As another method of providing a convex portion having an inclined surface between the heat sink 7a and the submount 5, the heat sink 7a made of a metal material such as silver, copper, iron or the like is processed into an integrated structure by a shaping method using a mold or the like. Alternatively, the convex portion 11d may be formed by projecting a part of the heat sink 7a. According to this method, the number of assembly members as a semiconductor laser can be reduced, and the assembly process can be shortened. Therefore, a large number of semiconductor lasers whose optical axis 21 is perpendicular to the main surface 25 of the stem are produced at low cost. There is an advantage that it can be manufactured.

Embodiment 5. FIG.
FIG. 5 is a sectional view showing the structure of a semiconductor laser according to the fifth embodiment. In the fifth embodiment, parts that are the same as or equivalent to those in the first embodiment shown in FIGS. 1A and 1B and the second embodiment shown in FIG. Is omitted, and only different parts will be described.

  In the first to fourth embodiments, in order to reduce the adverse effect on the reliability of the semiconductor laser caused by the stress due to the difference between the thermal expansion coefficients of the heat sink and the laser chip, the heat sink and the laser chip that constitute the chip mounting structure are reduced. A structure in which a submount having a thermal expansion coefficient close to that of a laser chip is interposed therebetween. However, in the fifth embodiment, as the heat sink, a material having a thermal expansion coefficient close to that of the laser chip and high thermal conductivity such as AlN (aluminum nitride) is used, so that the heat sink can be directly used without using a submount. A laser chip is fixed to the semiconductor laser to avoid adverse effects on reliability as a semiconductor laser.

  In the fifth embodiment, as shown in FIG. 5, the heat sink 7b constituting the chip mounting structure is perpendicular to the active layer 3 of the laser chip 1 and is laser-like, as in the second embodiment of FIG. The cross section including the optical axis 21 has an inclined surface 71 whose width in the direction parallel to the stem main surface 25 decreases as the distance from the stem 9 increases, and above the fixing surface 4 forming a part of the inclined surface 71. In addition, the laser chip 1 is directly fixed so that the surface on the active layer 3 side is in contact without using a submount.

  Here, the inclination angle β from the direction perpendicular to the stem main surface of the inclined surface 71 is set to be the same value (β = θ) as the inclination angle θ of the laser optical axis 21. Since the laser chip 1 is fixed to the fixing surface 4 on the inclined surface 71, the laser chip 1 is effectively inclined counterclockwise as in the first to fourth embodiments.

  As a result, the extension surface 23 of the fixing surface 4 of the laser chip 1 is also inclined to the heat sink 7a side by the same angle as θ, and viewed from the heat sink 7b side formed by the extension surface 23 (ie, the inclined surface 71) and the stem main surface 25. The angle α1 is smaller than 90 °, that is, α1 = (90−θ) °. Here, the inclination angle θ of the laser optical axis 21 is about 0.5 ° to 5 ° in the case of the high-power laser according to the fifth embodiment, and therefore, the perpendicular line between the inclined surface 71 and the stem main surface 25. Is also set to 0.5 ° to 5 °. The actual value of the angle α1 is, for example, α1 = (90−θ) ° = 87 ° when the tilt angle of the laser optical axis 21 is θ = 3 °.

  As a result, as shown in FIG. 5, the inclination of the laser resonator end face 20 of the laser optical axis 21 is apparently compensated when viewed from the outside of the package, and the laser light is emitted accurately in the vertical direction with respect to the stem main surface 25. become.

  In the fifth embodiment, since the submount can be omitted from the heat sink and the submount constituting the chip mounting structure, the laser optical axis 21 is accurately perpendicular to the main surface 25 of the stem at low cost. There is an advantage that a semiconductor laser compensated to be can be manufactured.

Embodiment 6 FIG.
FIG. 6 is a sectional view showing the structure of a semiconductor laser according to the sixth embodiment. In the sixth embodiment, the same or corresponding parts as those in the first embodiment shown in FIGS. 1A and 1B, the third embodiment shown in FIG. 3, and the fifth embodiment shown in FIG. The same reference numerals are attached and the description is omitted, and only different parts will be described.

  In the fifth embodiment, the entire surface of the heat sink 7b to which the submount 5 is fixed is the inclined surface. However, in the sixth embodiment, the heat sink 7c is similar to the third embodiment in FIG. In the cross-sectional shape, the inclined surface 72 is formed at a part above the surface to which the submount 7c is fixed so that the width in the direction parallel to the stem main surface 25 decreases as the distance from the stem 9 increases. The laser chip 1 is installed with the surface on the active layer 3 side fixed to the fixing surface 4 which is a part of the inclined surface 72 on the heat sink 7c.

  Here, the inclination angle β of the inclined surface 72 with respect to the perpendicular to the stem main surface 25 is set to be the same value as the angle θ of inclination of the laser optical axis 21, that is, β = θ. Since the laser chip 2 is fixed to the fixing surface 4 on the inclined surface 72, the laser chip 1 is effectively inclined counterclockwise as in the second to fifth embodiments.

  Accordingly, the extension surface 23 of the fixing surface 4 of the laser chip 1 is also inclined to the heat sink 7c side by the same angle as θ, and the angle α1 viewed from the heat sink 7c side formed by the extension surface 23 and the stem main surface 25 is 90 °. A smaller angle, that is, α1 = (90−θ) °.

  Here, as described above, the inclination angle θ of the laser optical axis 21 is about 0.5 ° to 5 ° in the case of the high-power laser according to the sixth embodiment. The angle β formed by the perpendicular line at 25 is also set to 0.5 ° to 5 °. Further, as the actual value of α1, for example, if the tilt angle of the laser optical axis 21 is θ = 3 °, α1 = (90−θ) ° = 87 °.

  As a result, as shown in FIG. 6, the inclination of the laser optical axis 21 at the laser resonator end face 20 is apparently compensated when viewed from the outside of the package, and the laser optical axis 21 is accurately perpendicular to the stem main surface 25.

  In the sixth embodiment, as in the fifth embodiment, the submount can be omitted from the heat sink and the submount constituting the chip mounting structure, so that the laser optical axis 21 with respect to the stem main surface 25 can be manufactured at low cost. There is an advantage that a semiconductor laser compensated to be accurately vertical can be manufactured.

  Further, in the chip mounting structure in which the laser chip is mounted, in the second and third embodiments, the laser chip 1 is fixed between the submount 5 and the submount 5 is installed on the heat sink 7b or 7c. In order to fix the two, two fixing locations are required, but in the sixth embodiment, the fixing location is reduced to one location between the heat sink 7c and the laser chip 1, so that the solder material used for fixing is used. The variation of the tilt angle of the laser chip 1 due to the variation in the thickness of the laser chip 1 is reduced, and a semiconductor laser in which the laser optical axis 21 is perpendicular to the stem main surface 25 more accurately can be manufactured. There is a merit.

  In addition to this, heat sinks with various angles of inclination can be easily manufactured by machining methods such as mechanical polishing to match existing model heat sinks with the inclination angle θ of the laser optical axis of the laser chip. The semiconductor laser has a merit similar to that of the third embodiment in that a semiconductor laser whose laser optical axis is accurately perpendicular to the main surface of the stem can be manufactured at low cost in accordance with the variation of each manufacturing lot of semiconductor lasers.

  In the second to sixth embodiments, the laser optical axis 21 emitted from the active layer 3 of the laser chip 1 is inclined toward the substrate 2 by the inclination angle θ from the vertical line 22 in the laser resonator end face 20. In a high-power laser made of an AlGaInP-based material, the inclination angle θ is about 0.5 ° to 5 °. Therefore, the inclined surfaces 71, 72, 73 of the heat sinks 7b, 7c and the wedge-shaped member 11d are used. And the angle formed by the perpendicular to the stem main surface 25 may be 0.5 ° to 5 °, respectively.

Embodiment 7 FIG.
7A and 7B are configuration diagrams showing the structure of the semiconductor laser according to the seventh embodiment. FIG. 7A is a cross-sectional view thereof, and FIG. 7B is a top view showing only the stem 9.
In the present embodiment, the same or corresponding parts as those in the first embodiment in FIGS. 1A and 1B and the second to sixth embodiments in FIGS. Thus, the description will be omitted, and only different parts will be described.

  In the first to sixth embodiments, the laser optical axis is accurately set with respect to the main surface of the stem by improving the submount or the heat sink constituting the chip mounting structure and substantially tilting the laser chip. In the seventh embodiment shown in FIG. 7, the chip mounting structure is formed by the conventional rectangular parallelepiped submount 5 and the heat sink 7a. 25 is installed in a recess 13g having an inclined surface 12g formed in a part of 25 to obtain a similar effect.

  In the seventh embodiment, as shown in FIG. 7, the position of the stem main surface 29 becomes lower than the stem main surface 25 as it proceeds on the stem main surface 25 in a direction away from the laser chip 1. A concave portion 13g having an inclined surface 12g is formed. On this inclined surface 12g, a chip mounting structure including a rectangular parallelepiped heat sink 7a and a rectangular parallelepiped submount 5 in which the active layer 2 side of the laser chip 1 is fixed on the fixing surface 4 is installed.

  In FIG. 7, the inclination angle β of the inclined surface 12g with respect to the stem main surface 25 in the recess 13g is set to the same value (β = θ) as the inclination angle θ of the laser optical axis 21 in the laser chip 1, and the heat sink 7a. Since the submount 5 is a rectangular parallelepiped, the extension surface 23 of the fixing surface 4 on the submount 5 of the laser chip 1 is inclined to the heat sink 7a side by the same angle as θ, and the extension surface 23 and the stem main surface The angle α1 viewed from the heat sink 7a side formed by 25 is an angle smaller than 90 °, that is, α1 = (90−θ) °. That is, the laser chip 1 is effectively inclined by the angle θ in the counterclockwise direction.

  As a result, as shown in FIG. 7, the inclination of the laser optical axis 21 at the laser resonator end face 20 is apparently compensated when viewed from the outside of the package, and the laser optical axis 21 is accurately perpendicular to the stem main surface 25. To be improved.

  In the seventh embodiment, the laser optical axis 21 emitted from the active layer 3 of the laser chip 1 is inclined to the substrate 2 side by the inclination angle θ from the perpendicular 22 in the laser resonator end face 20, and is usually an AlGaInP system. In the high-power laser made of a material, the inclination angle θ is 0.5 ° to 5 °. Therefore, the inclination angle β of the inclined surface 12g of the concave portion formed in the stem main surface 25 with respect to the stem main surface 25 is also 0. What is necessary is just to set it as 5 degrees-5 degrees.

  According to the seventh embodiment, the recess 13g having the inclined surface 12g is formed in the stem 9 by using a shaping method using a mold or the like in the manufacturing process of the stem 9 without performing special processing on the stem main surface 25. Therefore, there is an advantage that a semiconductor laser in which the laser optical axis 21 is accurately perpendicular to the stem main surface 25 can be manufactured at low cost.

  In the seventh embodiment, the case where the laser chip 1 is installed on the heat sink 7a via the submount 5 has been described. However, as in the fifth and sixth embodiments, the laser chip 1 is mounted. The same effect can be obtained even if it is installed directly on the heat sink 7a.

  In the seventh embodiment, the case where the submount 5 and the heat sink 7a are rectangular parallelepipeds has been described. However, the submount 5 and the heat sink 7a may each be a cube, and the same effect can be obtained by using a plate-like parallel plate as the submount.

Embodiment 8
8A and 8B are configuration diagrams showing the structure of the semiconductor laser according to the eighth embodiment. FIG. 8A is a sectional view, and FIG. 8B is a top view showing only the stem 9. In the present embodiment, the same or corresponding parts as those in the first embodiment in FIGS. 1A and 1B and the fourth and seventh embodiments in FIGS. 4 and 7 are denoted by the same reference numerals. Therefore, only the different parts will be described.

  In the seventh embodiment, a concave portion having an inclined surface 12g is formed on a part of the stem main surface 25, and the chip mounting formed by the submount 5 and the heat sink 7a made of a conventional rectangular parallelepiped member on the inclined surface 12g. The laser optical axis 21 is made to be accurately perpendicular to the stem main surface 25 by installing the structural body. However, as in the eighth embodiment, the stem 9 has an inclined surface 12h. Even if the convex portion 11h is formed, the same effect can be obtained.

  In the eighth embodiment, as shown in FIG. 8, in a cross section that is perpendicular to the active layer 3 of the laser chip 1 and includes the laser optical axis 21 in a partial region of the stem main surface 25, A wedge-shaped convex portion 11 h having an inclined surface 12 h whose position becomes higher than the stem main surface 25 as it goes in the direction closer to the laser chip 1 is formed.

  As a method for forming the convex portion 11h, for example, when the stem 9 is formed of a hermetic seal in which a low melting point glass is fused to a metal frame, a metal main body 25 forming the stem main surface 25 in the manufacturing process is formed. By raising the surface of the frame by a shaping method using a mold or the like, the convex portion 11h can be easily formed on the stem main surface 25 as an integral structure.

  On the inclined surface 12h, a chip mounting structure including a heat sink 7a and a submount 5 each formed of a rectangular parallelepiped member, and a laser chip fixed so that the active layer 2 side is in contact with the fixing surface 4 on the submount 5 1 is installed.

  In FIG. 8, the inclination angle β of the convex portion 11h with respect to the stem main surface 25 is set to the same value (β = θ) as the inclination angle θ of the laser optical axis 21 in the laser chip 1, and the heat sink 7a and Since the submount 5 is a rectangular parallelepiped, the extension surface 23 of the fixing surface 4 on the submount 5 of the laser chip 1 is inclined toward the heat sink 7a by the same angle as θ. Therefore, the angle α1 viewed from the heat sink 7a side formed by the extension surface 23 and the stem main surface 25 is smaller than 90 °, that is, α1 = (90−θ) °. That is, the laser chip 1 is effectively inclined by the angle θ in the counterclockwise direction.

  As a result, as shown in FIG. 8, the inclination of the laser optical axis 21 at the laser resonator end face 20 is apparently compensated when viewed from the outside of the package, so that the laser optical axis 21 is accurately perpendicular to the stem main surface 25. To be improved.

  In the eighth embodiment, the laser optical axis 21 emitted from the active layer 3 of the laser chip 1 is inclined toward the substrate 2 by the inclination angle θ from the vertical line 22 in the laser resonator end face 20, and is usually AlGaInP. In a high-power laser made of a system material, the inclination angle θ is 0.5 ° to 5 °. Therefore, the inclination angle β of the inclined surface of the convex portion formed on the stem main surface 25 with respect to the stem main surface is 0.5. What is necessary is just to make it 5 degrees.

  Further, according to the eighth embodiment, the convex portion 11h having the inclined surface 12h is formed on the main surface 25 using a mold or the like in the manufacturing process of the stem 9 without performing special processing on the stem main surface 25. Moreover, since it can be fabricated as an integral structure, there is a merit that a semiconductor laser that emits light perpendicularly to the stem main surface 25 can be fabricated at low cost.

  In the eighth embodiment, an example in which the convex portion 11h having the inclined surface 12h is formed as an integral structure of the stem 9 on the stem main surface 25 is shown. A wedge-shaped member having 12h may be prepared and installed on the stem main surface to form the convex portion 11h.

  In the eighth embodiment, the laser chip 1 is installed on the heat sink 7 via the submount 5. However, the laser chip 1 is installed directly on the heat sink 7a without using the submount. The same effect can be obtained.

  In the eighth embodiment, the case where the submount 5 and the heat sink 7a are rectangular parallelepipeds has been described. However, a cube may be used, and the same effect may be obtained even if a thin plate-like parallel plate is used as the submount. Is obtained.

Embodiment 9
FIG. 9 is a block diagram showing the structure of the semiconductor laser according to the ninth embodiment. In the figure, the same or corresponding parts as those of the first, fourth, seventh, and eighth embodiments shown in FIGS. 1, 4, 7, and 8 are denoted by the same reference numerals and the description thereof is omitted, and only different parts are described. explain.

  In the first to eighth embodiments, the main stem surface on the side where the laser chip of the stem is mounted is used as an optical reference surface, and the purpose is to compensate so that the laser optical axis is accurately perpendicular to the reference surface. However, depending on the design of the optical system of the semiconductor laser application device, the lower surface of the stem (hereinafter referred to as the stem lower surface) can be used as a reference surface of the optical system in the optical application device such as an optical pickup. In the ninth embodiment, the chip mounting structure including the submount 5 and the heat sink 7a is inclined on the stem lower surface 26 having the stem main surface as an optical reference surface, and the stem main surface 25b is inclined. By mounting, the laser optical axis 21 is made to be exactly perpendicular to the reference plane.

  In the ninth embodiment, as shown in FIG. 9, the stem main surface 25b is inclined with respect to the stem lower surface 26, which is an optical reference surface, at an angle β. The inclination direction of the stem main surface 25b is closer to the lower surface as it goes in the direction from the laser chip 1 toward the heat sink 7a (left side in FIG. 9) on the stem main surface 25b. It is the direction to go down. The tilt angle β is set to the same value (β = θ) as the tilt angle θ of the laser optical axis 21 in the laser chip 1.

  On the inclined stem main surface 25b, chip mounting structures each comprising a rectangular parallelepiped heat sink 7a and a submount 5 are installed. On the fixing surface 4 on the submount 5, the laser chip 1 is attached to the active layer 3 thereof. It is fixed and installed so that the surface of the side touches. The chip mounting structure is installed on the stem main surface 25b so that the laser optical axis 21 of the laser chip 1 is in a substantially vertical direction (upward) of the stem main surface 25b.

  Since the laser chip 1 is installed on the stem main surface 25b inclined by an angle β (= θ) via the rectangular parallelepiped submount 5 and the heat and the sink 7a, the laser chip 1 and the submount 5 are fixed. An angle α1 viewed from the heat sink 7a side formed by the extended surface 23 of the surface 4 and the stem lower surface 26 is an angle smaller than 90 °, that is, α1 = (90−θ) °. That is, the laser chip 1 is effectively inclined by the angle θ in the counterclockwise direction.

  As a result, as shown in FIG. 9, the inclination of the laser resonator end face 20 of the laser optical axis 21 is apparently compensated when viewed from the outside of the package, and the laser optical axis 21 is accurately with respect to the stem lower surface 26 serving as an optical reference plane. Improved to be vertical.

  According to the ninth embodiment, the stem 9b having the inclined stem main surface 25b can be easily manufactured using a mold or the like in the manufacturing process without adding special processing or parts, so that the cost is low. Thus, there is an advantage that a semiconductor laser in which the laser optical axis is accurately perpendicular to the stem lower surface 26 serving as an optical reference surface can be manufactured with a high yield.

  In the ninth embodiment, the case where the laser chip 1 is installed on the heat sink 7a via the submount 5 is shown. However, the same effect can be obtained even if the laser chip 1 is installed directly on the heat sink 7a. .

  In the ninth embodiment, the submount 5 and the heat sink 7a have been described as rectangular parallelepipeds. However, each of the submounts 5 and the heat sink 7a may be a cube. Is obtained.

Embodiment 10
10A and 10B are configuration diagrams showing the structure of the semiconductor laser according to the tenth embodiment. FIG. 10A is a cross-sectional view, and FIG. 10B is a top view showing only the stem 9. In the figure, portions that are the same as or equivalent to those of the seventh embodiment in FIG. 7 are denoted by the same reference numerals, description thereof is omitted, and only different portions are described.

  In the seventh embodiment (FIG. 7), the so-called junction down type in which the laser chip 1 whose laser optical axis 21 is inclined toward the substrate 2 is fixed so that the surface on the active layer 3 side is in contact with the submount 5. The case where the laser chip 1 is installed in the chip mounting structure according to the form, and this chip mounting structure is installed in the concave portion 13g having the inclined portion 12g provided in the stem main surface 25 has been described. In the tenth embodiment, as shown in FIG. 10, the laser optical axis 21 is accurately set to the main stem of a semiconductor laser assembled in a so-called junction-up type in which the substrate 2 side of the laser chip 1 is fixed to the submount 5. An assembly structure that is perpendicular to the surface 25 will be described.

  In the tenth embodiment, as shown in FIG. 10, in a partial region of the stem 9, as the position of the stem main surface 25 advances from the heat sink 7 a side toward the laser chip 1, the position of the stem 9 increases. A recess 13j having an inclined surface 12j that is lower is formed in the stem 9. On this inclined surface 12j, a chip mounting structure comprising a cuboid heat sink 7a and a submount 5 is installed, and the laser chip 1 is in contact with the substrate 2 side on the fixing surface 4 on the submount 5. It is fixed and installed.

  Further, the heat sink 7a, which is a part of the chip mounting structure, has a configuration in which the emission direction of the laser light is substantially perpendicular to the stem main surface 25, that is, above the stem 9. It is installed on the inclined surface 12j.

  In FIG. 10, the inclination angle β of the inclined surface 12j of the recess 13j with respect to the stem main surface 25 is set to the same value (β = θ) as the inclination angle θ of the laser optical axis 21 in the laser chip 1, and the heat sink 7a and the submount 5 are rectangular parallelepipeds, the extension surface 23 of the fixing surface 4 on the submount 5 of the laser chip 1 is inclined to the opposite side of the heat sink 7a by the same angle θ as the extension surface 23. The angle α2 viewed from the heat sink 7a side formed by the stem main surface 25 is an angle larger than 90 °, that is, α2 = (90 + θ) °. That is, the laser chip 1 is effectively inclined by the angle θ in the clockwise direction.

  As a result, as shown in FIG. 10, even in the semiconductor laser installed on the submount 5 by the junction-up method, the inclination of the laser optical axis 21 toward the substrate with respect to the perpendicular at the laser resonator end face 20 is viewed from the outside of the package. As a result, the laser optical axis 21 is improved so as to be exactly perpendicular to the stem main surface 25.

  Further, according to the tenth embodiment, the recess 13j having the inclined surface 12j is formed in the stem 9 by using a die or the like in the manufacturing process of the stem 9 without performing special processing on the stem main surface 25. Since it can be fabricated, there is a merit that a semiconductor laser compensated so that the laser optical axis 21 is accurately perpendicular to the stem main surface 25 can be fabricated at low cost.

  In the tenth embodiment, the laser chip 1 is installed on the heat sink 7 via the submount 5. However, the laser chip 1 is installed directly on the heat sink 7a without using the submount 5. However, the same effect can be obtained.

Embodiment 11
11A and 11B are configuration diagrams showing the structure of the semiconductor laser according to the eleventh embodiment. FIG. 11A is a cross-sectional view, and FIG. 11B is a top view showing only the stem 9. In the figure, portions that are the same as or equivalent to those of the eighth embodiment in FIG. 8 are denoted by the same reference numerals, description thereof is omitted, and only different portions are described.

  In the eighth embodiment (FIG. 8), the laser chip 1 whose laser optical axis 21 is inclined toward the substrate 2 is fixed to the submount 5 on the active layer 3 side, that is, the chip is assembled by the junction down method. Although the semiconductor laser manufactured by installing the mounting structure on the inclined surface 12h of the convex portion 11h has been described, in the eleventh embodiment, as shown in FIG. Regarding a semiconductor laser whose surface is fixed to the submount 5, that is, assembled by the junction down-up method, a structure in which the laser optical axis is set to be perpendicular to the stem main surface 25 will be described.

In the eleventh embodiment, as shown in FIG. 11, a heat sink is formed on the stem main surface 25 in a partial region of the stem 9 in a cross section perpendicular to the active layer 3 of the laser chip 1 and including the laser optical axis 21. As it advances from 7a toward the laser chip 1, a wedge-shaped cross-sectional convex portion 11k having an inclined surface 12k whose position approaches the stem main surface 25, that is, whose height is reduced, is formed. .
This wedge-shaped convex portion 11k having a cross-sectional shape is raised in a region of the stem main surface 25 using a shaping method using a mold or the like in the manufacturing process of the stem 9 as in the eighth embodiment shown in FIG. It can be built as an integrated structure.

  A chip mounting structure comprising a cuboid heat sink 7a and a submount 5 is installed on the inclined surface 12k, and the laser chip 1 is placed on the substrate 2 side on the fixing surface 4 on the submount 5. It is installed so that it touches, that is, a junction-up system.

  The heat sink 7a, which is a part of the chip mounting structure, has a configuration in which the laser light emission direction is substantially perpendicular to the stem main surface 25, that is, the laser light emission direction is above the stem 9. It is installed on the inclined surface 12k.

  In FIG. 11, the inclination angle β of the convex portion 11k with respect to the stem main surface 25 is set to the same value (β = θ) as the inclination angle θ of the laser optical axis 21 in the laser chip 1, and the heat sink 7a and Since the submount 5 is a rectangular parallelepiped (the angle between adjacent surfaces is 90 °), the extension surface 23 of the fixing surface 4 in the submount 5 of the laser chip 1 is inclined to the heat sink 7a side by the same angle as the angle θ. The angle α2 viewed from the heat sink 7 side formed by the extended surface 23 and the stem main surface 25 is an angle larger than 90 °, that is, α2 = (90 + θ) °. That is, the laser chip 1 is effectively inclined by the angle θ in the clockwise direction.

  As a result, as shown in FIG. 11, even in a semiconductor laser in which the laser optical axis 21 installed on the submount 4 is inclined to the substrate 2 side by the junction-up method, the perpendicular 22 on the laser resonator end face 20 of the laser optical axis 21. The inclination toward the substrate 2 side is apparently compensated when viewed from the outside of the package, and the laser optical axis 21 is improved so as to be accurately perpendicular to the stem main surface 25.

  Further, according to the eleventh embodiment, the convex portion 11k having the inclined surface 12k is formed on the main surface 25 using a mold or the like in the manufacturing process of the stem 9 without performing special processing on the stem main surface 25. Moreover, since it can be fabricated as an integral structure, there is an advantage that a semiconductor laser in which the laser optical axis 21 is accurately perpendicular to the stem main surface 25 can be fabricated at low cost.

  In the eleventh embodiment, the convex portion 11k having the inclined surface has been described as an integral structure in which a part of the stem main surface 25 is raised, but is separately manufactured on the stem 9 having a flat surface. It goes without saying that the same effect can be obtained even if a member having a wedge-shaped cross section is installed on the stem main surface 25.

In the eleventh embodiment, the laser chip 1 is installed on the heat sink 7a via the submount 5. However, the laser chip 1 is installed directly on the heat sink 7a without using the submount 5. However, the same effect can be obtained.

Embodiment 12
FIG. 12 is a sectional view showing the structure of a semiconductor laser according to the twelfth embodiment. In the figure, portions that are the same as or equivalent to those of the ninth embodiment in FIG. 9 are denoted by the same reference numerals, description thereof is omitted, and only different portions are described.

  In the ninth embodiment (FIG. 9), the chip mounting structure in which the laser chip 1 with the laser optical axis 21 inclined toward the substrate 2 is mounted by the junction down method is installed on the inclined stem main surface 25b. In the twelfth embodiment, as shown in FIG. 12, the substrate 2 side of the laser chip 1 is fixed to the submount 5, that is, the laser chip 1 is mounted by the junction-up method. Regarding the chip mounting structure, a configuration in which the laser optical axis 21 is accurately perpendicular to the stem lower surface 26 serving as an optical reference surface using the stem 9c having the inclined stem main surface 25c will be described.

In the twelfth embodiment, as shown in FIG. 12, the stem main surface 25c is inclined at an angle β with respect to the stem lower surface 26 serving as an optical reference surface.
The inclination direction of the stem main surface 25c is closer to the stem lower surface 26 as it goes on the stem main surface 25c from the heat sink 6 toward the laser chip 1 (right side in FIG. 12). This is the direction in which the position of the main surface 25c is lowered. The tilt angle β is set to the same value (β = θ) as the tilt angle θ of the laser optical axis 21 on the laser resonator end face 20.

A chip mounting structure composed of a rectangular parallelepiped heat sink 7a and a submount 5 is installed on the inclined main surface 25c. Further, on the fixing surface 4 on the submount 5, the laser chip 1 is on the active layer 3 side. It is installed so that it touches.
The chip mounting structure is installed on the stem main surface 25b in such a manner that the laser optical axis 21 of the laser chip 1 is substantially perpendicular to the stem main surface 25c, that is, above.

  As described above, the laser chip 1 is installed on the stem main surface 25b inclined by an angle β (= θ) through the rectangular parallelepiped submount 5 and the heat sink 7a. Thus, the angle α2 viewed from the heat sink 7a side formed by the extended surface 23 of the fixing surface 4 of the laser chip 1 and the submount 5 and the stem lower surface 26 is an angle larger than 90 °, that is, α2 = (90 + θ) °. It becomes. That is, the laser chip 1 is effectively inclined by the angle θ in the clockwise direction.

  As a result, as shown in FIG. 12, the tilt of the laser optical axis 21 at the laser resonator end face 20 is apparently compensated when viewed from the outside of the package, so that the laser optical axis 21 is accurately with respect to the stem lower surface 26 serving as an optical reference plane. Improved to be vertical.

  Further, according to the twelfth embodiment, the stem 9c having the inclined stem main surface 25 can be easily manufactured using a mold or the like in its manufacturing process without adding special processing or parts. There is an advantage that a semiconductor laser in which the laser optical axis is accurately perpendicular to the stem lower surface 26 serving as an optical reference surface can be manufactured at low cost and with high yield.

  In the seventh to twelfth embodiments described above, the laser chip 1 is installed on the heat sink 7a via the submount 5. However, the same effect can be obtained if the laser chip 1 is installed directly on the heat sink 7a. Is obtained.

  In the first to twelfth embodiments, the case where the laser chip of the high-power laser for writing on the optical disk using the AlGaInP-based material has been described. However, other AlGaAs-based, InGaAsP-based, AlGaInN (GaN) -based materials, etc. Needless to say, the present invention can also be applied to the case of using a laser chip made of a material.

  In the first to seventh embodiments, the heat sinks 7a, 7b, and 7c have been described as independent members separate from the stem. However, the heat sinks 7a, 7b, and 7c are manufactured as an integral structure with the stem 9 from the beginning. Needless to say, the effect does not change.

  In the first to twelfth embodiments, the laser chip, the submount, the heat sink, and the stem are fixed by using, for example, an alloy solder having an appropriate composition ratio and melting point such as AuSi and AuSn. As a result, assembly stress can be suppressed and practical fixing strength can be obtained.

  In Embodiments 2 to 4 or Embodiments 7 to 12, as in Embodiment 1, the material of the submount 5 is silicon having a high thermal conductivity and a thermal expansion coefficient close to that of the substrate. By using at least one of (Si), aluminum nitride (AlN), silicon carbide (SiC), diamond (C), and copper tungsten (CuW), the laser beam has good temperature characteristics and reliability. It is possible to realize a semiconductor laser whose axis is exactly perpendicular to the stem main surface or the stem lower surface serving as an optical reference surface.

  In the second to twelfth embodiments, as in the first embodiment, the heat sinks 7a, 7b, and 7c are made of silver (Ag) or copper (Cu) that has high thermal conductivity and is easy to process. By using at least one material selected from iron (Fe) and aluminum (Al), good temperature characteristics and low cost can be realized, and the laser main axis is the optical reference plane. A semiconductor laser that is accurately perpendicular to the surface or the bottom surface of the stem can be realized.

It is a block diagram which shows the structure of the semiconductor laser by Embodiment 1 of this invention. It is sectional drawing which shows the structure of the semiconductor laser by Embodiment 2 of this invention. It is sectional drawing which shows the structure of the semiconductor laser by Embodiment 3 of this invention. It is sectional drawing which shows the structure of the semiconductor laser by Embodiment 4 of this invention. It is sectional drawing which shows the structure of the semiconductor laser by Embodiment 5 of this invention. It is sectional drawing which shows the structure of the semiconductor laser by Embodiment 6 of this invention. It is a block diagram which shows the structure of the semiconductor laser by Embodiment 7 of this invention. It is a block diagram which shows the structure of the semiconductor laser by Embodiment 8 of this invention. It is sectional drawing which shows the structure of the semiconductor laser by Embodiment 9 of this invention. It is a block diagram which shows the structure of the semiconductor laser by Embodiment 10 of this invention. It is a block diagram which shows the structure of the semiconductor laser by Embodiment 11 of this invention. It is sectional drawing which shows the structure of the semiconductor laser by Embodiment 12 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser chip 2 Substrate 3 Active layer 4 Laser chip fixed surface 5 Submount 6 Submount installation surface 7a, 7b, 7c Heat sink 8 Heat sink installation surface 9 Stem 11d Convex part 11h, 11k on heat sink On stem main surface Convex portions 12h, 12k Inclined surfaces 12g, 12j formed in the convex portions Inclined surfaces 13g, 13j formed in the concave portions Concave portions 20 on the stem main surface 20 Laser resonator end surface 21 Laser optical axis 22 Vertical line 23 on the laser resonator end surface Laser Extension surface 25 of chip fixing surface Stem main surface 26 Stem lower surface

Claims (16)

A semiconductor laser having a double heterostructure formed on a semiconductor substrate, wherein the central axis of the laser beam emitted from the active layer in the double heterostructure is inclined toward the substrate side with respect to the perpendicular to the end face of the laser resonator A chip, a semiconductor laser chip mounting structure to which the active layer side surface of the semiconductor laser chip is fixed, and a stem on which the semiconductor laser chip mounting structure is installed. A semiconductor laser device in which the semiconductor laser chip mounting structure is installed on the stem main surface so as to be substantially perpendicular to the main surface, the semiconductor laser chip and the semiconductor laser chip mounting structure, The angle seen from the semiconductor laser chip mounting structure side formed by the extension surface of the fixing surface to which the is fixed and the stem main surface is smaller than 90 ° By tilting the serial fixing surface, a semiconductor laser device characterized by the central axis of the laser beam was set to be perpendicular to the stem main surface. The semiconductor laser chip mounting structure includes a submount and a heat sink on which the submount is mounted. The submount is perpendicular to the active layer of the semiconductor laser chip and includes a central axis of the laser beam. 2. A semiconductor laser device according to claim 1, wherein said semiconductor laser device has an inclined surface whose width in the direction parallel to the stem main surface decreases with increasing distance, and the inclined surface is used as a fixed surface. The semiconductor laser chip mounting structure includes a submount and a heat sink on which the submount is mounted. The heat sink is separated from the stem in a cross section perpendicular to the active layer of the semiconductor laser chip and including the central axis of the laser beam. 2. A semiconductor laser device according to claim 1, wherein said semiconductor laser device has an inclined surface whose width in the direction parallel to the stem main surface decreases in accordance with said surface, and the surface of the submount installed on said inclined surface is a fixing surface. . The semiconductor laser chip mounting structure comprises only a heat sink, and the heat sink is perpendicular to the active layer of the semiconductor laser chip and includes a central axis of the laser beam. 2. The semiconductor laser device according to claim 1, wherein the semiconductor laser device has an inclined surface that decreases in width, and the inclined surface is a fixing surface. 5. The semiconductor laser device according to claim 2, wherein an angle formed between the inclined surface and a perpendicular to the stem main surface is 0.5 to 5 °. 2. The semiconductor laser device according to claim 1, wherein a concave portion having an inclined surface is formed in a partial region of the stem main surface, and a semiconductor laser chip mounting structure is provided on the inclined surface. 2. The semiconductor laser device according to claim 1, wherein a convex portion having an inclined surface is formed in a partial region of the stem main surface, and a semiconductor laser chip mounting structure is provided on the inclined surface. 8. The semiconductor laser device according to claim 6, wherein an angle formed between the inclined surface and a perpendicular line on the stem main surface is 0.5 to 5 [deg.]. A semiconductor laser having a double hetero structure formed on a semiconductor substrate, wherein the central axis of the laser light emitted from the active layer in the double hetero structure is inclined toward the substrate side with respect to the perpendicular to the end face of the laser resonator A chip, a semiconductor laser chip mounting structure to which the active layer side surface of the semiconductor laser chip is fixed, and a stem on which the semiconductor laser chip mounting structure is installed. A semiconductor laser device in which the semiconductor laser chip mounting structure is installed on a stem main surface so as to be substantially perpendicular to the main surface, wherein the stem main surface is inclined with respect to the lower surface of the stem, and the inclined The semiconductor laser chip mounting structure was installed on the stem main surface, and the semiconductor laser chip and the semiconductor laser chip mounting structure were fixed. By tilting the fixing surface in a direction in which the angle seen from the semiconductor laser chip mounting structure side formed by the extension surface of the landing surface and the lower surface of the stem is smaller than 90 °, the central axis of the laser beam is relative to the lower surface of the stem. A semiconductor laser device characterized by being vertical. A semiconductor having a double heterostructure formed on a semiconductor substrate, wherein the central axis of the laser beam emitted from the active layer in the double heterostructure is inclined toward the substrate side with respect to the direction perpendicular to the laser resonator end face At least a laser chip, a semiconductor laser chip mounting structure to which the surface of the semiconductor laser chip on the substrate side is fixed, and a stem on which the semiconductor laser chip mounting structure is installed. A semiconductor laser device in which a semiconductor laser chip mounting structure is installed on a stem main surface so as to be substantially perpendicular to the main surface, and a recess having an inclined surface is formed in a partial region of the stem main surface Then, the semiconductor laser chip mounting structure is installed on the inclined surface, and the bonding surface between the semiconductor laser chip and the semiconductor laser chip mounting structure is extended. By tilting the fixing surface in a direction in which the angle seen from the semiconductor laser chip mounting structure side formed by the surface and the stem main surface is larger than 90 °, the central axis of the laser beam is perpendicular to the stem main surface A semiconductor laser device characterized by that. A semiconductor having a double heterostructure formed on a semiconductor substrate, wherein the central axis of the laser beam emitted from the active layer in the double heterostructure is inclined toward the substrate side with respect to the direction perpendicular to the laser resonator end face At least a laser chip, a semiconductor laser chip mounting structure to which the surface of the semiconductor laser chip on the substrate side is fixed, and a stem on which the semiconductor laser chip mounting structure is installed. A semiconductor laser device in which the semiconductor laser chip mounting structure is installed on a stem main surface so as to be substantially perpendicular to the main surface, and a convex portion having an inclined surface in a partial region of the stem main surface And mounting the semiconductor laser chip mounting structure on the inclined surface, and a fixing surface between the semiconductor laser chip and the semiconductor laser chip mounting structure By tilting the fixing surface in a direction where the angle seen from the semiconductor laser chip mounting structure side formed by the extension surface and the stem main surface is larger than 90 °, the central axis of the laser beam is relative to the stem main surface. A semiconductor laser device characterized by being vertical. 12. The semiconductor laser device according to claim 10, wherein an angle formed between the inclined surface and the stem main surface is 0.5 to 5 degrees. A semiconductor laser having a double hetero structure formed on a semiconductor substrate, wherein the central axis of the laser light emitted from the active layer in the double hetero structure is inclined toward the substrate side with respect to the perpendicular to the end face of the laser resonator A semiconductor laser chip mounting structure to which the substrate side surface of the semiconductor laser chip is fixed, and a stem on which the semiconductor laser chip mounting structure is installed. A semiconductor laser device in which the semiconductor laser chip mounting structure is installed on a stem main surface so as to be substantially perpendicular to the surface, wherein the stem main surface is inclined with respect to the lower surface of the stem and is inclined A semiconductor laser chip mounting structure is installed on the stem main surface, and the semiconductor laser chip and the semiconductor laser chip mounting structure are fixed to each other. By tilting the fixing surface in a direction in which the angle seen from the semiconductor laser chip mounting structure side formed by the extended surface of the surface and the lower surface of the stem is larger than 90 °, the central axis of the laser beam is perpendicular to the lower surface of the stem A semiconductor laser device characterized by that. 14. The semiconductor laser device according to claim 9, wherein an angle formed between the stem main surface and the stem lower surface is 0.5 to 5 [deg.]. The semiconductor laser device according to claim 9, wherein the semiconductor laser chip mounting structure includes at least one of a submount and a heat sink on which the submount is mounted. The submount material is at least one of silicon (Si), aluminum nitride (AlN), silicon carbide (SiC), diamond (C), and copper tungsten (CuW), and the heat sink material is silver (Ag) and copper (Cu The semiconductor laser device according to claim 1, wherein at least one of iron (Fe) and aluminum (Al) is used.

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