DE102023111589B3 - Low-stress optical bench with thermal decoupling - Google Patents

Abstract

The present invention relates to a device for arranging optical components in a thermally decoupled housing (LH), in particular an optical bench (OB) suspended with little tension and thermally decoupled from a laser housing, which is suitable for mobile and satellite-based applications, for example in quantum information technology and quantum sensor technology.A device according to the invention for arranging optical components in a housing (LH) comprises a housing (LH); an optical bench (OB), monolithically formed from a rigid material with high thermal conductivity and yield strength; at least two spring elements (SE) acting in the plane of the optical bench (OB) on the outer edges of the optical bench (OB), wherein the optical bench (OB) is attached to base elements (PE) of the housing (LH) exclusively via the spring elements (SE) and the optical bench (OB) is held cantilevered in the housing (LH) via the base elements (PE); clamping rails (CB) below the spring elements (SE); Thermal insulators (TI) beneath the clamping rails (CB), whereby the clamping rails (CB) rest at least in sections on the thermal insulators (TI) and the clamping rails (CB) can be stably supported by these against the base elements (PE) of the housing (LH); and a thermally conductive strip (TS).

Description

The present invention relates to a device for arranging optical components in a thermally decoupled housing, in particular a low-stress suspended micro-optical bench that is thermally decoupled from a laser housing and is suitable for mobile and satellite-based applications, for example in quantum information technology and quantum sensor technology.

State of the art

• • klein, leicht und kompakt sein,
• • eine hohe intrinsische mechanische Stabilität aufweisen, insbesondere während des Starts zu einer Weltraummission,
• • eine Temperaturkontrolle des opto-mechanischen Aufbaus ermöglichen, und
• • eine sehr hohe thermische Stabilität des gesamten opto-mechanischen Aufbaus während des Betriebs gewährleisten können.

For a wide range of applications, for example in quantum information technology, quantum sensing, optical clocks and coherent satellite communications, laser modules are required that can realize and provide an ultra-stable frequency reference with a small line width. For the operation of laser modules outside of optical laboratories, such as in field operation for applications in quantum computing and especially for use on a satellite platform, the laser modules must meet particularly high technical requirements. The laser modules must, among other things:

• • be small, light and compact,
• • have a high intrinsic mechanical stability, especially during launch for a space mission,
• • enable temperature control of the opto-mechanical structure, and
• • ensure a very high thermal stability of the entire opto-mechanical structure during operation.

Since there are currently no suitable laser modules in the state of the art that can meet all these technical requirements simultaneously, a low-stress (micro)optical bench is required that is thermally decoupled from a housing but coupled to a dynamically controllable environment for temperature stabilization.

In the state of the art, temperature-stabilized housing solutions for particularly compact (diode) laser modules are usually designed as butterfly housings (see e.g. Lyakh, Arkadiy, et al. “1.6 W high wall plug efficiency, continuous-wave room temperature quantum cascade laser emitting at 4.6 µm.” Applied Physics Letters 92.11 (2008): 111110.) These usually use an electro-thermal converter (also called a Peltier element, or thermo-electric cooler, TEC), which is located inside the laser housing and usually carries the laser chip and associated collimation optics. The TEC generally has an upper ceramic substrate, which can be viewed as an optical bench (OB), and acts as a support for all active and passive optical components of the laser structure. However, the footprint of the OB is limited to the maximum footprint of the TEC used, which is capped by technical restrictions. In the prior art, a lens is typically used to collimate the output facet of the laser chip, but this lens is usually not attached to the upper ceramic substrate of the TEC and is therefore not considered part of the OB and the temperature stabilization.

A disadvantage of such butterfly packages is their size limitation. The footprint (length × width) of the OB is limited to the maximum size of the TEC used. The footprint of the TEC in such assemblies is typically only about 20 × 20 mm ² to 25 × 25 mm ² to avoid damage during assembly and operation due to thermo-mechanical expansion of the upper (commonly referred to as cold) ceramic substrate relative to the lower (commonly referred to as hot) ceramic substrate and the lower (hot) ceramic substrate relative to the package. It should also be noted that if the package is mechanically deformed by external forces, this can have a direct effect on the OB and cause misalignment of the optical components.

EN 10 2022 101 921 A1 relates to a holding arrangement with a carrier platform to which at least one optical element is fixed, wherein the holding arrangement is intended to ensure improved beam position stability with the least possible effort. In US6,771,437 B1 Optical bench mounting and thermal management techniques are disclosed to enable increased stability. CN 1 15 799 973 A shows a heat dissipation packaging structure for a semiconductor laser.

Another temperature-stabilized housing solution for compact satellite-compatible (diode) laser modules is described in Kürbis et al. ( Pumpkin, Ch. et al. “Extended cavity diode laser master-oscillator-power-amplifier for operation of an iodine frequency reference on a sounding rocket.” Applied Optics 59.2 (2020): 253-262 .) revealed (see 1 ). It is known that the OB of a satellite-compatible laser module should be mechanically robust and have the lowest possible coefficient of thermal expansion. In order to avoid thermo-mechanical optical misalignment, precise temperature stabilization using a TEC is typically also implemented in satellite-compatible laser systems.

In the 1 In the laser structure shown, the OB is made of aluminum nitride for mechanical stabilization and is glued to a housing (laser housing, LH) made of Kovar ® using a thermally conductive adhesive (TCA). The OB is thus firmly connected to the LH. All electrical and optical components and the diode laser chip are integrated on the top side of the ceramic body of the OB. The LH is screwed to a mounting plate (MP; not shown), which also functions as a heat sink. The distance between the LH and the MP is determined using a module spacer (MS), which serves both for mechanical positioning (of the LH on the MP) and for thermal insulation (between the LH and the MP). A TEC is arranged between the LH and the MP (centered under the LH), which is therefore located outside the LH. To improve heat conduction, thermally conductive and flexible thermal interface material (TIM) pads can be placed between the LH and the TEC and between the TEC and the MP. The TEC is used to precisely control the temperature of the OB, e.g. the TEC enables heat to be dissipated and the temperature of the OB to be stabilized if the temperature of the LH or the heat load on the OB changes.

The footprint of the OB of such a laser module can be significantly larger than that of a butterfly housing, for example the 1 The OB shown has a footprint of typically about 30 × 80 mm ² . In other laser modules of this type, OBs with an area of about 60 × 95 mm ² have also been realized. However, even with this type of housing solution, if the LH is mechanically deformed by external forces, this has a direct impact on the OB. This can lead to misalignment of the optical components. In addition, a temperature change of the LH also has a direct impact on the temperature of the OB and causes thermal expansion, which can lead to a shift in the laser frequency. In addition, with strong temperature fluctuations, relatively large shear stresses can occur on the OB if the thermal expansion coefficients of the LH and the OB do not match. Therefore, the OB can be stretched and bent, which in turn can lead to optical misalignment. Finally, the temperature control of the OB by the TEC below the LH requires the stabilization of a non-negligible total thermal mass by the material volume of the LH. In addition, the TEC offers only a small control bandwidth (slow temperature control) due to the relatively large thermal resistance of the control loop and the relatively large thermal resistance along the heat flow path via TIM, TCA and LH.

Disclosure of the invention

It is therefore an object of the present invention to provide a low-stress optical bench with good thermal coupling to the environment, which avoids the disadvantages of the prior art or at least significantly reduces them. In particular, a micro-optical bench is to be provided which is suspended with low stress and is thermally well decoupled from a housing and which is suitable for mobile and satellite-based applications, for example in quantum information technology and quantum sensor technology.

These objects are achieved according to the invention by the features of the independent patent claim. Useful embodiments of the invention are contained in the associated dependent claims. The features listed individually in the patent claims can be combined with one another in a technologically meaningful manner and can be supplemented by explanatory facts from the description and/or details from the figures, whereby further embodiments of the invention are shown.

A device according to the invention for arranging optical components in a housing comprises a housing; an optical bench, monolithically formed from a rigid material with high thermal conductivity and yield strength; at least two spring elements acting in the plane of the optical bench on the outer edges of the optical bench, wherein the optical bench is attached to base elements of the housing exclusively via the spring elements and the optical bench is held in the housing in a self-supporting manner via the base elements; clamping rails below the spring elements; heat insulators below the clamping rails, wherein the clamping rails rest at least in sections on the heat insulators (also referred to as thermal insulators) and the clamping rails are stably supported by these with respect to the base elements of the housing; and a heat-conducting tape, wherein a first end of the heat-conducting tape is fixed to a self-supporting area of the optical bench and a second end of the heat-conducting tape is fixed between a base element and a clamping rail next to a heat insulator.

The housing can be, in particular, a laser housing for accommodating a (diode) laser arrangement on the optical bench. However, the present invention is not limited to such applications and can, for example, also be applied to a detector housing for accommodating a pure detector arrangement on the optical bench. The housing can be made of stainless steel, Kovar ® or aluminum, for example.

The material of the optical bench should be rigid, i.e. have as high a modulus of elasticity E as possible. The material preferably has a modulus of elasticity E of over 70 GPa, more preferably over 100 GPa, even more preferably over 200 GPa. The thermal conductivity κ should also be as high as possible, values over 75 W/(m·K) are preferred, more preferably over 150 W/(m·K), even more preferably over 200 W/(m·K). The yield strength R _e is the mechanical stress up to which a material can be elastically deformed. In this respect, this value should also be as high as possible. For technical materials, the more precisely determined so-called 0.2% proof stress (also known as elastic limit R _p0.2 ) is usually specified instead of the yield strength. Preferred values for the 0.2% yield strength are over 200 MPa, more preferably over 300 MPa, even more preferably over 500 MPa. A particularly high yield strength (or 0.2% yield strength) is preferred because the material of the optical bench can be used to mechanically decouple the optical bench from the environment and plastic deformations under mechanical stress must be avoided at all costs. The optical bench is preferably a micro-optical bench. In the context of this application, micro-optical benches are understood to mean optical benches with a maximum area of up to about 10,000 mm ² (e.g. an optical bench with an area of 60 × 95 mm ² ). However, the present invention is not restricted to such micro-optical benches.

The spring elements on the outer edges of the optical bench should act in particular in the plane of the optical bench. This allows different expansions of the optical bench and the housing to be compensated. In addition, however, the spring elements can also have a spring component that acts perpendicular to the plane of the optical bench. In addition to the aforementioned expansion compensation, this also allows compensation for any bending between the housing and the optical bench. The spring elements can thus be designed to act in different directions.

The base elements of the housing are designed to provide support and support points for a cantilevered mount for the optical bench. The base elements should be sufficiently high compared to the base of the housing to keep both the optical bench and the heat conducting strips, which are preferably arranged on the underside, away from the base of the housing.

The invention solves the technical problem of mounting the optical bench in the housing in such a way that the mechanical and thermomechanical stress and deformation are kept away from the optical bench and at the same time a good thermal decoupling of the optical bench from the housing is enabled.

In particular, the optical bench can also be decoupled from mechanical stress from the environment. Mechanical stresses that can arise from the mechanical deformation of the laser housing or from a relative thermal expansion or contraction of the optical bench and/or the housing are not transferred to the optical bench, since the flexible and mechanically stress-carrying solid-state structures can absorb all stresses and deformations that occur due to changes in the environment. This means that the material of the housing can also differ from the material of the optical bench.

The spring elements are preferably solid-state joint structures arranged in the same plane as the optical bench. The solid-state joint structures can be designed to act in different directions. The solid-state joint structures can preferably act in the plane of the optical bench and perpendicular to this plane. The spring elements can also comprise narrow webs and tapered areas, through which extensive mechanical decoupling can be achieved between the self-supporting optical bench and the sections of the individual spring elements that are firmly connected to the base elements of the housing. In particular, the spring elements can absorb stresses that occur between the housing and the optical bench, so that they cannot affect the optical bench.

Preferably, the spring elements are formed monolithically in the material of the optical bench. This enables a homogeneous formation of the structures and increases their reliability. Alternatively, however, the spring elements can also be formed independently of the optical bench from the same or a different material as the optical bench and connected to it. Connection can be made, for example, by soldering, welding, gluing, screwing or a combination thereof.

Preferably, the optical bench is made of a Mo ₇₀ Cu ₃₀ alloy, Kovar ® or another metallic or ceramic material. The use of Mo ₇₀ Cu ₃₀ alloy is particularly preferred because the material Mo ₇₀ Cu ₃₀ has the properties of being non-magnetic, having a low gas content, offering high thermal conductivity and a low coefficient of thermal expansion, being suitable for vacuum applications and being easy to process. In addition, it has a coefficient of thermal expansion that largely corresponds to that of GaAs (a material typically used for laser chips). A Mo ₇₀ Cu ₃₀ alloy for forming an optical bench is not yet known in the prior art. Instead of a particularly preferred Mo ₇₀ Cu ₃₀ alloy, however, a different Mo _x Cu _100-x alloy with x between 50 and 90, more preferably between 60 and 80, can also be used. A suitable ceramic material can be, for example, aluminum oxide or aluminum nitride.

Preferably, the optical bench is connected to the base elements in the housing via a screw connection, a solder connection, a weld connection, a clamp connection, an adhesive connection or a combination thereof. In addition to the easy detachability of the connection, a screw connection offers the advantage of being particularly reliable and simple.

Preferably, the first end of the thermally conductive tape is attached to the optical bench via a soldered connection, a welded connection, an adhesive connection or a clamped connection. To improve the heat transfer, a thermally conductive pad can be arranged between the first end of the thermally conductive tape and the optical bench.

Preferably, an electro-thermal converter is arranged between the second end of the heat conducting tape and the base element. Alternatively or additionally, a resistance heater can also be arranged between the second end of the heat conducting tape and the base element. In particularly cold environments (Arctic, space), for example, the resistance heater can be used in addition to the electro-thermal converter to heat the optical bench and thus provide a "thermal offset" to provide basic heat even without the possibility of rapid control by an electro-thermal converter. If rapid temperature control is not required, however, the resistance heaters can also be used without additional electro-thermal converters.

Preferably, an electro-thermal converter or resistance heater arranged between the second end of the thermally conductive strip and the base element contacts the second end of the thermally conductive strip on its top and/or bottom side directly or via a thermally conductive pad. Fixing can be carried out, for example, by soldering, welding, gluing, clamping or a combination thereof.

An optical bench according to the invention offers significant advantages over the solutions known in the prior art. The optical bench according to the invention can be attached to the housing using screws. The optical bench can carry as optical components, for example lenses, mirrors, polarization optics (retardation plates, polarizers), electro-optical or acousto-optical modulators, laser chips, gas cells and/or discrete electronics (temperature sensors, TEC, photodiodes, etc.) in order to function as a laser, spectroscopy device, module for beam switching, beam distribution or beam merging, for generating laser pulses or as a combination thereof.

The spring elements may be provided by cutting out some portions of a material providing the optical bench to provide flexible and resilient mechanical structures (including bends, tapers and joints).

The electro-thermal transducers or resistance heaters, the thermal pads and the thermal insulators can be completely housed inside the housing and arranged between the optical bench and the housing. Therefore, the heating or cooling of the optical bench can be controlled by the operation of the electro-thermal transducers or resistance heaters, and the optical bench and the housing are thermally decoupled from each other. A change in the temperature of the housing thus does not affect the temperature of the optical bench, since the electro-thermal transducers or resistance heaters, the thermal pads and the thermal insulators between the optical bench and the laser housing make it possible to control the temperature of the optical bench independently of the temperature of the housing.

Flexible thermal tapes can connect the bottom of the optical bench to the electro-thermal transducers or resistive heaters to create specific paths for heat transfer. The thermal tapes can be glued to the optical bench with one end using a thermally conductive adhesive and attached to the electro-thermal transducers or resistive heaters with the other end. The thermal tapes enable thermal contact between the optical bench and the electro-thermal transducers or resistive heaters. mixed transducers or resistance heaters without creating a strong mechanical coupling between the optical bench and the electro-thermal transducers or resistance heaters. Compared to the state of the art, the electro-thermal transducers or resistance heaters can be arranged much closer to the optical bench, which reduces the thermal resistance between the housing and the optical bench and enables improved and faster temperature regulation of the optical bench.

Compared to devices according to the prior art, the present invention is also significantly more robust against vibrations, mechanical deformations and loads as well as against temperature fluctuations, since the optical bench is not rigidly connected to the housing due to the spring elements and is thermally decoupled from the housing due to the specific design of the heat paths.

In some embodiments of the present invention, the spring elements can be designed in such a way that they are not flexible in all directions and their arrangement and properties are selected so that the optical bench assumes a defined position. However, the optical bench should not be freely "floating" in the housing via the spring elements; rather, the spring elements should only follow deformations of the housing through appropriate adjustment and be able to absorb the mechanical forces and stresses that occur without the optical bench being deformed as a result.

• • ultrastabiler Uhrenlaser in einem optischen Atomuhrensystem,
• • lokaler Oszillator für kohärente (Inter-)Satelliten-Kommunikation,
• • Lasersystem für neutrale atom- oder ionenbasierte Quantenberechnungen, sowie
• • Lasersystem für die atominterferometrische Trägheitsnavigation oder für die Gravitationsgradiometrie.

The present invention can be used, for example, as:

• • ultra-stable clock laser in an optical atomic clock system,
• • local oscillator for coherent (inter-)satellite communication,
• • Laser system for neutral atom- or ion-based quantum calculations, as well as
• • Laser system for atom interferometric inertial navigation or for gravitational gradiometry.

The present invention can further be used to implement photonic modules and systems that enable laser beam control, e.g., for pulse generation, beam combining and distribution, and the like. In general, the invention supports the miniaturization of both photonic and electro-optic solutions.

Further preferred embodiments of the invention result from the features mentioned in the respective subclaims.

The various embodiments of the invention mentioned in this application can be advantageously combined with one another, unless stated otherwise in individual cases.

Short description of the drawings

• 1 eine schematische Darstellung einer Vorrichtung zur Anordnung optischer Komponenten gemäß Stand der Technik;
• 2 eine schematische Darstellung einer Ausführungsform einer erfindungsgemäßen Vorrichtung zur Anordnung optischer Komponenten; und
• 3 eine schematische Darstellung der erfindungsgemäßen Vorrichtung zur Anordnung optischer Komponenten nach 2 im Querschnitt.

The invention and the technical environment are explained in more detail below with reference to the accompanying figures. It should be noted that the invention is not intended to be limited by the exemplary embodiments given. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the facts explained in the figures and combine them with other components and findings from the present description. They show:

• 1 a schematic representation of a device for arranging optical components according to the prior art;
• 2 a schematic representation of an embodiment of a device according to the invention for arranging optical components; and
• 3 a schematic representation of the device according to the invention for arranging optical components according to 2 in cross section.

Detailed description of the drawings

1 shows a schematic representation of a device for arranging optical components according to the state of the art. The device shown is a housing for compact satellite-compatible (diode) laser modules according to Kürbis ( Pumpkin, Ch. et al. “Extended cavity diode laser master-oscillator-power-amplifier for operation of an iodine frequency reference on a sounding rocket.” Applied Optics 59.2 (2020): 253-262 .), in which the optical bench OB is made of aluminum nitride for mechanical stabilization and is bonded to a housing LH made of Kovar ® using a thermally conductive adhesive TCA. The optical bench OB is thus firmly connected to the housing LH. All electrical and optical components and the diode laser chip are integrated on the top of the ceramic body of the optical bench OB.

The housing LH is screwed to a mounting plate (MP; not shown), which also functions as a heat sink. The distance between the housing LH and the mounting plate MP is determined by a module distance holder (English: module spacer, MS) is specified, which serves both for mechanical positioning (of the housing LH on the mounting plate MP) and for thermal insulation (between the housing LH and the mounting plate MP). An electro-thermal converter (Peltier element) TEC is arranged between the housing LH and the mounting plate MP (centrally under the housing LH), which is therefore located outside the housing LH. To improve heat conduction, thermally conductive and flexible thermal interface material (TIM) can be arranged between the housing LH and the electro-thermal converter TEC and between the electro-thermal converter TEC and the mounting plate MP. The electro-thermal converter TEC is used for precise temperature control of the optical bench OB, e.g. the electro-thermal converter TEC enables heat to be dissipated and the temperature of the optical bench OB to be stabilized if the temperature of the housing LH or the heat load on the optical bench OB changes.

2 shows a schematic representation of an embodiment of a device according to the invention for arranging optical components. The device comprises a housing LH (not shown in the illustration); an optical bench OB, monolithically formed from a rigid material with high thermal conductivity and yield strength; at least two spring elements SE acting in the plane of the optical bench OB (ie against the outer edges) on the outer edges of the optical bench OB, the optical bench OB being attached to base elements PE of the housing LH exclusively via the spring elements SE and the optical bench OB being held in a self-supporting manner via the base elements PE in the housing LH; clamping rails CB below the spring elements SE; Thermal insulators TI below the clamping rails CB, wherein the clamping rails CB rest at least in sections on the thermal insulators TI and the clamping rails CB are stably supported by these with respect to the base elements PE of the housing LH, and a thermally conductive strip TS, wherein a first end of the thermally conductive strip TS is fixed to a self-supporting region of the optical bench OB and a second end of the thermally conductive strip TS is fixed between a base element PE and a clamping rail CB next to a thermal insulator TI.

The housing LH can in particular be a laser housing for accommodating a (diode) laser arrangement on the optical bench OB. However, the present invention is not restricted to such applications and can, for example, also relate to a detector housing for accommodating a detector arrangement on the optical bench OB.

The spring elements SE are solid-state joint structures arranged in a plane with the optical bench OB. The solid-state joint structures can be designed to act in different directions. The solid-state joint structures can preferably act in the plane of the optical bench OB and perpendicular to this plane. The spring elements SE can, as shown, comprise narrow webs (acting in the plane of the optical bench OB) and tapered areas (acting perpendicular to the plane of the optical bench OB), through which a substantial mechanical decoupling is achieved between the self-supporting optical bench OB and the sections of the individual spring elements SE that are firmly connected to the base elements PE of the housing LH. In particular, stresses that occur via the spring elements SE due to different expansion or bending between the housing LH and the optical bench OB can be absorbed so that they cannot affect the optical bench OB. However, the present invention is not limited to the solid-state joint structures shown only as examples in the illustration.

In the illustration, the spring elements SE are formed monolithically in the material of the optical bench OB. However, the spring elements SE can also be formed independently of the optical bench OB from the same or a different material as the optical bench OB and connected to it. The optical bench OB is preferably made of a Mo ₇₀ Cu ₃₀ alloy, Kovar ® or another metallic or ceramic material.

The optical bench OB shown is connected to the base elements PE in the housing LH via a screw connection. Alternatively, however, a soldered connection, a welded connection, a clamped connection, an adhesive connection or a combination thereof can also be used. The first end of the thermally conductive tape TS is preferably attached to the optical bench OB via a soldered connection, an adhesive connection, a welded connection or a clamped connection.

An electro-thermal converter (Peltier element) TEC is arranged between the second end of the heat conducting strip TS and the base element PE. Instead of the electro-thermal converter TEC or in addition to it, a resistance heater can also be arranged between the second end of the heat conducting strip TS and the base element PE. An electro-thermal converter TEC or resistance heater arranged between the second end of the heat conducting strip TS and the base element PE can heat the second end of the Contact the top and/or bottom of the thermal conductive tape TS directly or via a thermal conductive pad TIM.

In particular, the device shown comprises six stainless steel screws SSS for fastening in a housing LH with two base elements PE (the housing is not shown in the illustration), twelve stainless steel washers SSW, six PEEK washers PW made of polyetheretherketone (PEEK), an optical bench OB, four spring elements SE, two clamping rails CB (one clamping rail CB each as a support for two adjacent spring elements SE), six heat insulators TI made of polyetheretherketone (PEEK), heat-conducting adhesive TCA, four thermal tapes TS, thermal heat-conducting pads TIM and four electro-thermal converters TEC. The assembly of such an exemplary preferred embodiment comprises a combination of gluing, pressing and screwing between the optical bench OB and the laser housing LH.

The optical bench OB preferably consists of a material that is new for these purposes, made of (pure) molybdenum and an (oxygen-free) copper alloy (Mo ₇₀ Cu ₃₀ ). Alternatively, a ceramic material such as aluminum nitride or another metallic material such as Kovar ® can be used to manufacture the optical bench OB. The ceramic material (aluminum nitride) used by Kürbis et al. is not suitable for the described embodiment of the present invention with screw connections, however, since it is not suitable for screwing due to its strength. A Mo ₇₀ Cu ₃₀ alloy for forming an optical bench is not known in the prior art. Instead of a particularly preferred Mo ₇₀ Cu ₃₀ alloy, however, a different Mo _x Cu _100-x alloy with x between 50 and 90, more preferably between 60 and 80, can also be used.

In the embodiment shown, four spring elements SE acting in the plane of the optical bench OB (i.e. against the outer edges) and perpendicular to this (i.e. with respect to bending upwards or downwards) are arranged on the outer edges of the optical bench OB at the corners of the rectangular optical bench OB. The four spring elements SE each contain a screw hole. In the screw holes there are four stainless steel screws SSS, with which the optical bench OB can be firmly connected to a base element PE of the housing LH. The optical bench OB is not, however, attached directly to the base elements PE of the housing LH, but via two clamping rails CB (arranged parallel on two opposite edges of the optical bench) and four heat insulators TI arranged underneath. The clamping rails CB, which can also be made of Mo ₇₀ Cu ₃₀ or another alloy corresponding to the material of the optical bench OB, are used to clamp all thermal-mechanical components, such as the heating elements. B. the thermal insulators TI, the thermal conduction strips TS, the thermal conduction pads TIM and the electro-thermal converters TEC. Each terminal block CB and each thermal insulator TI also contains appropriately arranged screw holes to enable the screw connection between a spring element SE and the corresponding base element PE of the housing LH.

The middle part of the optical bench OB, on which the optical components are arranged, is suspended inside the housing LH on mechanical solid-state joint structures and does not touch the bottom of the housing LH. The solid-state joint structures are aligned and positioned in such a way that they can ensure isostatic support of the optical bench OB relative to the housing LH. The flexible and mechanical stress-absorbing solid-state joint structures shown can ensure isostatic support in particular when the joints are freely rotatable, can bend/deform freely in the intended direction and are approximately infinitely stiff for any other deformation. With the help of this isostatic or almost isostatic support, the deformation of the optical bench OB, which results from mechanical deformation of the housing LH or deformation due to thermally induced expansion or contraction of the housing LH or the optical bench OB or both, can be significantly reduced compared to previous solutions in the state of the art.

The stainless steel screws SSS (including the stainless steel washers SSW) do not have direct contact with the surface of the optical bench OB, but are thermally decoupled via PEEK washers PW in between. The PEEK washers PW are used to reduce direct heat transfer between the housing LH and the optical bench OB along the stainless steel screws SSS and stainless steel washers SSW. In addition, the PEEK washers SSW provide high mechanical strength. By using thermal insulators TI, direct heat flow between the housing LH and the spring elements SE via the fastening areas of the stainless steel screws SSS is avoided, while at the same time a vertical space is provided for the middle part of the optical bench OB to prevent contact with the bottom of the housing LH.

Four thermally conductive strips TS are mounted beneath the optical bench OB. A first end of each of the thermally conductive strips TS can be attached to a central, lower part of the optical bench OB using a thermally conductive adhesive TCA. The second end can also be attached to a clamping rail CB using a thermally conductive adhesive TCA.

Four electro-thermal converters TEC are mounted below the second ends of the heat conducting strips TS and are connected to them via optional intermediate heat conducting pads TIM on the top of the TEC. The underside of the electro-thermal converters TEC is connected to the bottom of the housing LH or to the base elements PE arranged therein, whereby a connection can also be made via optional intermediate heat conducting pads TIM. The heat conducting strips TS are used to define the path for heat transfer from the optical bench OB to the electro-thermal converters TEC, whereby a thermal short circuit between the edges of the optical bench OB supported by the spring elements SE and the corresponding corners of the housing LH is avoided or suppressed via the heat insulators TI. The heat conducting pads TIM are preferably used to ensure good thermal conductivity between the electro-thermal converters TEC and the housing LH as well as between the electro-thermal converters TEC and the heat conducting strips TS.

An additional combination of module spacer MS and mounting plate MP as in the prior art is not required, since the electro-thermal converters TEC are arranged inside the housing LH in the embodiment of the invention shown. The clamping rails CB distribute the forces introduced via the stainless steel screws evenly across the assembly consisting of the electro-thermal converters TEC, the thermally conductive strips TS and the thermally conductive pads TIM and fix them firmly to one another in the installation space of the housing LH.

In addition, as shown in the diagram, two additional sets of stainless steel screws SSS and stainless steel washers SSW, PEEK washers PW and thermal insulators can be used in the middle of the two clamping bars CB through additional screw holes in the clamping bars CB. This can prevent uneven compression of the clamping bars onto the underlying components, which can cause bending and large horizontal displacement (under shock and vibration) of the TEC, thermal tapes TS and thermal insulators TIM.

3 shows a schematic representation of the device according to the invention for arranging optical components according to 2 in cross section. The individual reference symbols and their respective associated features apply accordingly. The same reference symbols belong to the same features. A detailed description of the individual features shown is therefore omitted. The description of the 2 is referred to. Both the self-supporting structure of the optical bench OB and the spring elements SE resting on the respective base elements PE can be seen on the respective outer edges of the optical bench OB. Thermal coupling of the optical bench OB with the environment or the housing LH is achieved via heat conducting strips TS.

List of reference symbols

MS

Module spacer

MP

Mounting plate

TIM

Thermal interface material

TEC

electro-thermal converter / Peltier element (thermo-electric cooler)

LH

(Laser) housing

TCA

thermally conductive adhesive

IF

optical bench

TS

Thermal strap

TI

Heat insulator (English “thermal isolator”)

CB

Clamping bar

SSS

Stainless steel screw

SSW

Stainless steel washer

PW

PEEK washer

P.E.

Pedestal element

SE

Spring element

Claims (10)

Device for arranging optical components in a housing (LH), comprising: a housing; an optical bench (OB), monolithically formed from a rigid material with high thermal conductivity and yield strength; at least two in the plane of the optical bench (OB) acting spring elements (SE) on the outer edges of the optical bench (OB), wherein the optical bench (OB) is attached to base elements (PE) of the housing (LH) exclusively via the spring elements (SE) and the optical bench (OB) is held in a self-supporting manner via the base elements (PE) in the housing (LH); clamping rails (CB) below the spring elements (SE); heat insulators (TI) below the clamping rails (CB), wherein the clamping rails (CB) rest at least in sections on the heat insulators (TI) and the clamping rails (CB) can be stably supported by these against the base elements (PE) of the housing (LH); and a heat conducting strip (TS), wherein a first end of the heat conducting strip (TS) is fixed to a self-supporting area of the optical bench (OB) and a second end of the heat conducting strip (TS) is fixed between a base element (PE) and a clamping rail (CB) next to a heat insulator (TI). Device according to Claim 1 , whereby the spring elements (SE) are solid-state joint structures arranged in the same plane as the optical bench (OB). Device according to Claim 1 or 2 , wherein the spring elements (SE) are formed monolithically in the material of the optical bench (OB). Device according to Claim 1 or 2 , wherein the spring elements (SE) are formed independently of the optical bench (OB) from the same or a different material as the optical bench (OB) and are connected to it. Device according to one of the preceding claims, wherein the optical bench (OB) is made of a Mo ₇₀ Cu ₃₀ alloy, Kovar ® or another metallic or ceramic material. Device according to one of the preceding claims, wherein the optical bench (OB) is connected to the base elements (PE) in the housing (LH) via a screw connection, a solder connection, a weld connection, a clamp connection or an adhesive connection. Device according to one of the preceding claims, wherein the first end of the heat-conducting tape (TS) is attached to the optical bench (OB) via a soldered connection, a welded connection, an adhesive connection or a clamped connection. Device according to one of the preceding claims, wherein an electro-thermal converter (TEC) is arranged between the second end of the heat-conducting strip (TS) and the base element (PE). Device according to one of the preceding claims, wherein a resistance heater is arranged between the second end of the heat conducting strip (TS) and the base element (PE). Device according to one of the preceding claims, wherein an electro-thermal converter (TEC) or resistance heater arranged between the second end of the heat-conducting strip (TS) and the base element (PE) contacts the second end of the heat-conducting strip (TS) at its top and/or bottom side directly or via a heat-conducting pad (TIM).