Optical module

Abstract

The present application provides an optical module. For example, an optical module of a new structure improved to suppress heat transfer to a device that affects the characteristics of light transmitted in a case where the device is heated from a heat generating portion. The optical module includes, for example, a housing that transmits light inside, a heat generating portion, a device provided in the housing that changes the characteristics of light transmitted in the housing in a case where the device is heated, and a first member that is thermally connected to the heat generating portion and the device, in which a hollow is provided in the first member on a heat transfer path from the heat generating portion to the device in a state where convective heat transfer to the housing is suppressed. The housing can be hermetically sealed, and in the first member, as the hollow, a hollow that is open to the outside of the housing can be provided, or a hollow that is a closed space can be provided.

Description

Technical Field

[0001] This invention relates to optical modules. Background Technology

[0002] Previously, an optical module was known to include optical devices, optical components, temperature control devices, etc., and to transmit light within a housing (e.g., Patent Document 1). Examples of optical devices include photodiodes and modulators.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: JP 2020-178117

[0006] Such optical modules sometimes contain heat-generating components within their housing, such as modulator drivers and chip-on-submount devices. In this case, if the optical devices and temperature control devices receive heat generated from the heat-generating components, the characteristics of the light transmitted within the housing may change, and consequently, the optical properties of the optical module may also change. Therefore, blocking heat from the heat-generating components to these optical devices and temperature control devices is an important issue. Summary of the Invention

[0007] Therefore, one of the objectives of this invention is, for example, to obtain an optical module with an improved structure that can suppress heat transfer from the heat-generating part to the device that affects the characteristics of light transmitted into the housing when heated.

[0008] The optical module of the present invention includes, for example: a housing that transmits light internally; a heating element; a device disposed within the housing that, when heated, causes a change in the characteristics of the light transmitted within the housing; and a first member that is thermally connected to the heating element and the device, wherein a cavity is provided in the first member along the heat transfer path from the heating element to the device, in a state that suppresses convective heat transfer into the housing.

[0009] In the optical module, the outer casing may also be hermetically sealed.

[0010] In the optical module, the first component may also have a cavity that opens to the outside of the outer casing, serving as the cavity.

[0011] In the optical module, the first component may also be provided with a cavity as a closed space.

[0012] In the optical module, the first component may also have a cavity providing an opening into the housing, and the optical module may include a covering component that at least partially covers the opening.

[0013] In the optical module, the covered component may also be at least one of a second component bonded to the first component and an adhesive that bonds the first component and the second component.

[0014] In the optical module, a cavity may also be provided in the first component, serving as the cavity, at least partially located within the outer casing.

[0015] In the optical module, a cavity may also be provided in the first component, as the cavity, located outside the outer shell.

[0016] In the optical module, the heating element and the device may be arranged with an open gap in the first direction, and in the first component, as the opening, a plurality of openings with an open gap in the first direction may be provided.

[0017] In the optical module, the heating element and the device may be arranged with an open gap in the first direction, and in the first component, as the cavity, a plurality of cavities are provided with an open gap in the second direction intersecting the first direction.

[0018] In the optical module, the first component may also have a cavity, which serves as the cavity, with a heat transfer layer having a higher thermal conductivity than the first component on its inner surface.

[0019] Alternatively, the optical module may have multiple devices as the devices, and in the first component, as the cavity, a cavity is provided in the heat transfer path between the multiple devices.

[0020] Alternatively, the optical module may have a heating element located inside the housing as the heating element.

[0021] Alternatively, the optical module may have a heating element located outside the housing as the heating element.

[0022] The optical module has a heating element that performs electrical operation.

[0023] In the optical module, the heating element can also be mounted on the first component via a flip chip.

[0024] Alternatively, the optical module may include a joint, which is a joint of multiple components, and is heated during the joining process.

[0025] In the optical module, the joint may also be located outside the housing, and in the first component, a cavity is provided outside the housing as a closed space.

[0026] In the optical module, the outer casing may also be the first component.

[0027] Alternatively, the optical module may have a support member that supports the device as the first member.

[0028] Alternatively, the optical module may have a fixing member that is fixed to the supporting member as the first member.

[0029] Alternatively, the optical module may have a first component made of a porous material as the first component.

[0030] The effects of the invention

[0031] According to the present invention, for example, an optical module with an improved new structure can be obtained. Attached Figure Description

[0032] Figure 1 This is an illustrative and schematic side view (partial cross-sectional view) showing the internal structure of the optical module in the first embodiment.

[0033] Figure 2 This is an illustrative and schematic top view of the rear of the optical module according to the first embodiment.

[0034] Figure 3 This is an illustrative and schematic cross-sectional view of a portion of the optical module in the second embodiment.

[0035] Figure 4 This is an illustrative and schematic side view (partial cross-sectional view) showing the internal structure of the optical module in the third embodiment.

[0036] Figure 5 This is an illustrative and schematic side view (partial cross-sectional view) showing the internal structure of the optical module in the fourth embodiment.

[0037] Figure 6 This is an illustrative and schematic side view (partial cross-sectional view) showing the internal structure of the optical module in the fifth embodiment.

[0038] Figure 7 This is an illustrative and schematic side view (partial cross-sectional view) showing the internal structure of the optical module in the sixth embodiment.

[0039] Figure 8 This is an illustrative and schematic cross-sectional view of a portion of the optical module in the sixth embodiment.

[0040] Figure 9 This is an illustrative and schematic side view (partial cross-sectional view) showing the internal structure of the optical module in the seventh embodiment.

[0041] Explanation of reference numerals in the attached figures

[0042] 10...Outer shell (first component, fixed component)

[0043] 10a…bottom wall

[0044] 10a1…back

[0045] 10b… Zhoubi

[0046] 10c…top wall

[0047] 10d… Window Components

[0048] 21, 21E... Feedthrough section (first component, support component)

[0049] 21a… conductor

[0050] 21b… conductor

[0051] 21c...covering conductor

[0052] 22... Support base (first component)

[0053] 23… clamped components

[0054] 31... Modulator driver (heating unit)

[0055] 32...Transimpedance Amplifier (Device)

[0056] 33… Modulator (device)

[0057] 34... Coherent mixer (device)

[0058] 35...Chip (device, heat-generating component) on substrate

[0059] 36...bonding wire

[0060] 41, 42...TEC (devices)

[0061] 51... Lens (Optical Component)

[0062] 52… Adhesive

[0063] 61, 61C1, 61C2…void

[0064] 61a…Opening

[0065] 61b…heat transfer layer

[0066] 61c…Opening

[0067] 62, 62C, 62G...void

[0068] 71…External wiring

[0069] 72…Joint

[0070] 81... Mounting base plate (first component, fixing component)

[0071] 82…Joint

[0072] 91...Heat conduction block (heat transfer component)

[0073] 92... Heat transfer plate (heat transfer component)

[0074] 93, 94... Radiators

[0075] 100, 100A~100G… Optical Modules

[0076] P1…First Part

[0077] S… containment chamber

[0078] X…direction

[0079] Y...direction

[0080] Z…direction Detailed Implementation

[0081] The following discloses exemplary embodiments of the present invention. The structure of the embodiments shown below, and the effects and results (effects) brought about by such structure, are examples. The present invention can also be implemented by structures other than those disclosed in the following embodiments. Furthermore, according to the present invention, at least one of various effects (including derived effects) obtained by the structure can be obtained.

[0082] The various embodiments shown below have the same structure. Therefore, based on the structure of each embodiment, the same function and effect can be obtained based on the same structure. Furthermore, the same reference numerals are used to refer to these same structures below, and repeated descriptions are sometimes omitted.

[0083] In this specification, the ordinal numbers are assigned for convenience in distinguishing components, parts, directions, etc., and do not indicate priority or order.

[0084] Furthermore, in each diagram, the X-direction is represented by arrow X, the Y-direction by arrow Y, and the Z-direction by arrow Z. The X, Y, and Z directions intersect and are orthogonal to each other.

[0085] [First Implementation]

[0086] Figure 1 This is a side view showing the internal structure of the optical module 100A (100) of the first embodiment. Furthermore, Figure 2This is a top view of the back of the bottom wall 10a of the housing 10 of the optical module 100A. In addition, the optical module 100 has, for example, the same structure as the optical module disclosed in PCT / JP2021 / 002326 (WO-A1-2021 / 153462).

[0087] like Figure 1 As shown, the optical module 100A includes a housing 10, a feedthrough section 21, a support base 22, and a clamping member 23.

[0088] The outer casing 10 has a bottom wall 10a, a peripheral wall 10b, and a top wall 10c. The bottom wall 10a has a generally quadrilateral and plate-like shape. The bottom wall 10a extends approximately orthogonally to the Z-direction and extends in the X and Y directions. The peripheral wall 10b extends approximately along the Z-direction with a generally fixed thickness from the edge of the bottom wall 10a. The peripheral wall 10b can also be referred to as a side wall. The top wall 10c has a generally quadrilateral and plate-like shape. Furthermore, the top wall 10c extends approximately orthogonally to the Z-direction and extends in the X and Y directions.

[0089] A light-transmitting window member 10d is provided between the interior and exterior of the outer casing 10 (reception chamber S) on the peripheral wall 10b. Light emitted from inside the outer casing 10 to outside the outer casing 10, light incident from outside the outer casing 10 to inside the outer casing 10, and light passing through devices and components inside the outer casing 10 are transmitted within the outer casing 10.

[0090] The bottom wall 10a can be made of materials with high thermal conductivity, such as copper-tungsten (CuW), copper-molybdenum (CuMo), or alumina (Al2O3). Furthermore, the peripheral wall 10b and the top wall 10c can be made of materials with low coefficients of thermal expansion, such as Fe-Ni-Co alloys or alumina (Al2O3).

[0091] The periphery of the top wall 10c, also called a cover, overlaps with the Z-direction end edge of the peripheral wall 10b in the Z direction. By joining the periphery of the top wall 10c and the Z-direction end edge of the peripheral wall 10b, a housing chamber S for housing components and devices is formed within the housing 10. Gases such as inert gases and air are contained within the housing chamber S (within the housing 10). Furthermore, the housing chamber S can be hermetically sealed.

[0092] The feed passage 21 has a conductor 21a and an insulating portion, penetrating a portion of the peripheral wall 10b of the housing 10. The conductor 21a of the feed passage 21 is made of a highly conductive metal material, such as copper-based metals. Furthermore, the insulating portion of the feed passage 21 is made of an insulator, such as ceramic. The boundary between the feed passage 21 and the housing 10 is, for example, insulated and hermetically sealed.

[0093] In addition, the feedthrough section 21 supports the modulator driver 31 and the transimpedance amplifier 32 (reference). Figure 2Such components.

[0094] like Figure 1 As shown, the support base 22 is fixed to the bottom wall 10a of the housing 10, and extends approximately perpendicular to the Z direction at a substantially fixed height in the Z direction. The support base 22 supports optical components such as the lens 51. The lens 51 is bonded and fixed to the support base 22 by an adhesive 52. Alternatively, the support base 22 may also be configured as a multilayer wiring substrate.

[0095] The clamped component 23 is located between the TEC41 (thermoelectric cooler, cooling mechanism) and the modulator 33 and coherent mixer 34 (reference). Figure 2 The TEC41 includes a Peltier element, through which the temperature of the modulator 33, coherent mixer 34, photodiode, etc., is electrically adjusted; it can also be called a temperature control mechanism. The clamping member 23 has a plate-like shape and can be made of a material with high thermal conductivity. Furthermore, the modulator 33 is electrically connected to the modulator driver 31 via bonding leads 36.

[0096] Furthermore, a TEC42, different from the TEC41, is provided on the bottom wall 10a, and a chip 35 (light-emitting unit) on the substrate is provided on the side opposite to the bottom wall 10a relative to the TEC42. Although the object to which the temperature is adjusted is different, the TEC42 has a structure that is roughly the same as that of the TEC41. In addition, the chip 35 on the substrate has a submount and a light-emitting element such as a semiconductor laser element mounted on the submount.

[0097] The modulator driver 31, transimpedance amplifier 32, modulator 33, coherent mixer 34, chip-on-a-substrate 35, TEC 41, 42, lens 51 and other components are housed in the housing 10. In addition to these components, the housing 10 may also house optical components (not shown), such as mirrors, beam combiners, beam splitters and optical isolators.

[0098] The modulator 33, coherent mixer 34, on-board chip 35, TEC 41, 42, etc., housed within the housing 10 are devices whose characteristics (e.g., wavelength) of light transmitted within the housing 10 may change if heated (hereinafter referred to as first devices). Other examples of such first devices include heaters, wavelength lockers as wavelength detectors, vertical resonator surface-emitting lasers (VCSELs), and modulator-integrated semiconductor lasers (EMLs).

[0099] Furthermore, the modulator driver 31, transimpedance amplifier 32, and on-board chip 35 generate heat during electrical operation. These modulator driver 31, transimpedance amplifier 32, and on-board chip 35 are examples of heat-generating components located within the housing 10.

[0100] In an optical module 100 with such a structure, if heat generated in the heating element is transferred to the first device, the characteristics of the light transmitted within the housing 10 will change, and consequently, the optical characteristics of the optical module 100 may change. Therefore, in this embodiment, cavities 61 and 62 are provided in components (hereinafter referred to as first components) that are thermally connected to the heating element and the first device, forming a heat transfer path (hereinafter referred to as a heat transfer path), such as the housing 10, the feedthrough 21, and the support substrate 22. The cavities 61 and 62 are positioned within the heat transfer path from the heating element to the first device, thus blocking heat transfer in the heat transfer path. In this embodiment, the cavities 61 and 62 are at least partially located within the housing 10 (within the housing S). The cavity 61 can be formed during the manufacturing of the component with the cavity 61, or it can be formed after assembling the optical module 100. The cavity 62 is formed during the manufacturing of the component with the cavity 62. In addition, the component of the first device, such as the support feed passage 21 in the first component, is an example of a support component, while the component fixed to the support component, such as the housing 10, is an example of a fixed component.

[0101] like Figure 1 As shown, a cavity 61 is provided in the feedthrough 21 and the bottom wall 10a. The cavity 61 extends in the Y and Z directions with a given width in the X direction and is provided in a slit shape. Furthermore, the cavity 61 is provided across the feedthrough 21 and the bottom wall 10a, and extends through the bottom wall 10a, opening on the back side 10a1 of the bottom wall 10a. That is, the cavity 61 is also referred to as a bottom hole. Through this cavity 61, heat transfer from the modulator driver 31 or transimpedance amplifier 32, which is a heat-generating element, to the modulator 33, coherent mixer 34, TEC41, etc., via the feedthrough 21 and the bottom wall 10a can be suppressed.

[0102] Here, assuming that the cavity 61 opens into the housing S, the gas inside the cavity 61 is heated by heat transfer through the feed passage 21 or the bottom wall 10a. This heat then moves into the housing S via convective heat transfer, heating the first device inside the housing S. As a result, the insulation effect provided by the cavity 61 may be weakened. Therefore, in this embodiment, the cavity 61 is configured to not communicate with the housing S, i.e., to suppress convective heat transfer from the cavity 61 to the housing S (within the outer casing 10).

[0103] Furthermore, the cavity 61 opens onto the back side 10a1 of the bottom wall 10a. In other words, the cavity 61 opens outwards from the outer shell 10. Thus, through convective heat transfer by the warm gas within the cavity 61, heat can escape from the opening on the back side 10a1 to the outside of the outer shell 10. Consequently, the heat retention within the cavity 61 and subsequently within the outer shell 10 is suppressed, enhancing the heat transfer suppression effect of the cavity 61.

[0104] In addition, such as Figure 2 As shown, in the feedthrough section 21, a plurality of holes 61 are arranged serially with spacing in the X direction and parallel with spacing in the Y direction. Wiring paths are sometimes provided within the feedthrough section 21, but if a large hole 61 is provided, it may be difficult to arrange the wiring path. Regarding this, in this embodiment, while suppressing heat transfer through the plurality of holes 61, the wiring path can be more easily secured by passing through the portion between the plurality of holes 61 (hereinafter referred to as the first portion P1).

[0105] Furthermore, in the feedthrough section 21, other holes 61 staggered in the X direction are arranged between two adjacent holes 61 with an open spacing in the Y direction. In other words, the multiple holes 61 are arranged differently from each other. Since the first part P1 becomes the heat transfer path, assuming that the multiple first parts P1 are arranged in the X direction, the heat transfer path becomes shorter and heat is more easily transferred. In this respect, in this embodiment, since the multiple holes 61 and the first parts P1 are arranged differently from each other, the heat transfer path through the first parts P1 can be made longer, and heat transfer through the feedthrough section 21 and the bottom wall 10a can be further suppressed.

[0106] In addition, such as Figure 1 As shown, a cavity 61 is also provided in the support base 22 and the bottom wall 10a. This cavity 61 spans the support base 22 and the bottom wall 10a, and extends through the bottom wall 10a, opening on the back side 10a1 of the bottom wall 10a. That is, the cavity 61 can also be referred to as a bottom hole. Through this cavity 61, heat transfer from the chip 35 on the substrate, which serves as a heat-generating part, to the modulator 33, coherent mixer 34, TEC41, etc., via the support base 22 and the bottom wall 10a can be suppressed. Furthermore, this cavity 61 is located on the heat transfer path between TEC41 and TEC42. Therefore, through the cavity 61, heat transfer between TEC41 and TEC42 via the support base 22 and the bottom wall 10a can be suppressed. In addition, TEC41 and 42 each have a cooling section and a heat-generating section, respectively. Therefore, through the cavity 61, heat transfer from the heat-generating parts of TEC41 and 42 to modulator 33, coherent mixer 34, and chip 35 on substrate can be suppressed via the support substrate 22 and bottom wall 10a.

[0107] Furthermore, although the support base 22 has an opening 61a leading into the receiving chamber S of the cavity 61, i.e., the outer casing 10, this opening 61a is blocked by at least one of the lens 51 and the adhesive 52. Therefore, by means of convective heat transfer from the cavity 61 to the receiving chamber S (within the outer casing 10), the weakening of the heat insulation effect caused by the cavity 61 can be suppressed. Furthermore, in this case, since the cavity 61 can be formed as a through hole, it is sometimes easier to form the cavity 61 than to form it as a bottomed hole that extends only halfway. The lens 51 and the adhesive 52 are examples of coating components. Furthermore, the lens 51 is an example of an optical component or component mounted on the first component.

[0108] Furthermore, the support base 22 also includes a cavity 62 that is closed within it. In other words, the cavity 62 is a closed space. The cavity 62 extends in the Y and Z directions with a given width in the X direction, and is provided in a slit-like manner. The cavity 62 is also provided in a state where it is not connected to the receiving chamber S, that is, in a state where convective heat transfer from the cavity 62 to the receiving chamber S (within the outer shell 10) is suppressed. Therefore, the cavity 62 can achieve the same function and effect as the cavity 61.

[0109] As explained above, in this embodiment, cavities 61 and 62 are provided in the heat transfer path of the first component that is thermally connected to the heating element and the first device. Therefore, according to this embodiment, since heat transfer from the heating element to the first device can be suppressed through the cavities 61 and 62, the characteristics of the light transmitted within the housing 10 can be suppressed from changing due to the heating of the heating element, thereby suppressing changes in the optical characteristics of the optical module 100.

[0110] Furthermore, cavities 61 and 62 and the housing S do not need to be completely isolated. As long as the temperature rise of the first device caused by convective heat transfer from cavities 61 and 62 does not substantially affect the characteristics of the light, cavities 61 and 62 and the housing S can be connected. That is, the lens 51 (component, optical component) or adhesive 52 can partially close the opening 61a of cavity 61 within this range.

[0111] [Second Implementation]

[0112] Figure 3 This is a cross-sectional view of the periphery of the cavity 61 in the optical module 100B (100) of the second embodiment. In this embodiment, the cavity 61 is also provided across the feedthrough portion 21 and the bottom wall 10a, similar to the first embodiment described above. In this embodiment, the same effect as the first embodiment can also be obtained based on the same structure.

[0113] In this embodiment, a heat transfer layer 61b with a higher thermal conductivity than the feedthrough portion 21 is provided on the inner surface of the cavity 61. Furthermore, the heat transfer layer 61b extends to the opening 61c of the cavity 61 located on the back side 10a1 of the bottom wall 10a of the housing 10. With this structure, heat dissipation from the periphery of the cavity 61 to the outside of the housing 10 is improved, thus further suppressing heat transfer from the heat-generating part to the first device.

[0114] [Third Implementation]

[0115] Figure 4 This is a side view showing the internal structure of the optical module 100C (100) according to the third embodiment. In this embodiment, as in the first embodiment described above, holes 61 and 62 are provided in the feedthrough portion 21, the support base 22, and the bottom wall 10a. In this embodiment, the same effect as in the first embodiment can also be obtained based on the same structure.

[0116] In this embodiment, some of the cavities 61 (61C1, 61C2) are bent or branched. With this structure, for example, arranging the cavities 61 in locations where temperatures are more likely to rise, can provide advantages such as improved heat dissipation from the cavities 61 or increased flexibility in wiring paths. Additionally, the cavities 62 can also be bent or branched.

[0117] Furthermore, in this embodiment, the conductor 21a of the feedthrough 21 and the conductor of the external wiring 71 are mechanically and electrically joined via a joint 72. The joint 72 is, for example, a brazing or welding joint that is heated and melted during joining and then cooled and solidified, and is conductive.

[0118] Furthermore, a cavity 62C, serving as a closed space, is provided in the feedthrough 21 at a location outside the outer casing 10. Through this cavity 62C, heat transfer from the heated joint 72 to components within the housing S (outer casing 10) such as the modulator driver 31 can be suppressed during the engagement of the joint 72. Here, the cavity 62C is provided as a closed space and preferably does not open to the outside of the feedthrough 21. This is because if the cavity 62C were open to the outside of the feedthrough 21, the heat dissipation from the periphery of the cavity 62C would increase, making it impossible to provide sufficient melting heat during the engagement of the joint 72.

[0119] [Fourth Implementation]

[0120] Figure 5This is a side view showing the internal structure of the optical module 100D (100) of the fourth embodiment. The optical module 100D of this embodiment has the same structure as the optical module 100C of the third embodiment, except that the conductor 21a of the feedthrough 21 passes through the feedthrough 21 in the Z direction. In this embodiment, the same effects based on the same structure as the third embodiment can also be obtained.

[0121] [Fifth Implementation]

[0122] Figure 6 This is a side view showing the internal structure of the optical module 100E (100) according to the fifth embodiment. In this embodiment, the same effect can be obtained based on the same structure as in the first embodiment described above.

[0123] In this embodiment, the optical module 100E replaces the bottom wall of the housing 10 and is provided with a feedthrough portion 21E. In other words, the feedthrough portion 21E functions as the bottom wall of the housing 10. The feedthrough portion 21E is configured as a multilayer wiring substrate.

[0124] First devices, such as modulator driver 31, transimpedance amplifier 32, modulator 33, coherent mixer 34, and on-board chip 35, are flip-chip mounted on feedthrough 21E and supported by feedthrough 21E. Optical components, such as lens 51, are fixed to feedthrough 21E via adhesive 52. Feedthrough 21E is an example of a first component and also an example of a support component.

[0125] The feedthrough section 21E is provided with a conductor 21b that electrically connects multiple electrical components.

[0126] The modulator driver 31, transimpedance amplifier 32, first device, and the top wall 10c of the housing 10 are thermally connected via heat transfer components such as a relatively rigid heat-conducting block 91 and a relatively soft heat-conducting sheet 92. The heat transfer components can be composed of a single heat-conducting block 91 or heat-conducting sheet 92, or a combination of both. Furthermore, heat dissipation components such as heat sinks 93 and 94 are fixed to the top wall 10c, exposed on the outside of the housing 10. This structure suppresses the temperature rise of the first device.

[0127] The insulating portion (general part) of the feedthrough section 21E can be made of a porous material such as machinable ceramic. In this case, the heat transfer rate of the feedthrough section 21E itself can be lowered, and heat transfer in the heat transfer path of the feedthrough section 21E can be suppressed.

[0128] Furthermore, the feedthrough section 21E (optical module 100E) is electrically and mechanically connected and fixed to the conductor of the mounting substrate 81 via a bonding portion 82 such as a solder bead. The mounting substrate 81 is an example of a fixing member. In addition, the mounting substrate 81 is thermally connected to the feedthrough section 21E, and via the feedthrough section 21E, is thermally connected to the heat-generating part and the first device. Therefore, the mounting substrate 81 is both an example of a first member and an example of a fixing member.

[0129] Furthermore, in this embodiment, holes 61 are provided in the heat transfer path of the feedthrough portion 21E, which is a first component and is thermally connected to the heating element and the first device, and in the mounting substrate 81. Therefore, according to this embodiment, since heat transfer from the heating element to the first device can be suppressed through the holes 61, the characteristics of the light transmitted within the housing 10 can be suppressed from changing due to the heating of the heating element, thereby suppressing changes in the optical characteristics of the optical module 100E.

[0130] [Sixth Implementation]

[0131] Figure 7 This is a side view showing the internal structure of the optical module 100F (100) of the sixth embodiment. The optical module 100F of this embodiment has the same structure as the optical module 100E of the fifth embodiment, except that it has a covering conductor 21c covering the open gap conductor 21b. In this embodiment, the same effects as in the fifth embodiment can also be obtained.

[0132] In addition, a cavity 62 is provided as a closed space in the feedthrough portion 21E, replacing the cavity 61. Furthermore, the cavity 62 is also provided on the mounting substrate 81.

[0133] Figure 8 It is a cross-sectional view intersecting the X direction at the portion containing conductor 21b and covering conductor 21c. For example... Figure 8 As shown, the covering conductor 21c is a bent plate-like member extending in the X direction with a generally U-shaped cross-section. It partially covers the conductor 21b on the side opposite to the feedthrough portion 21E, and is electrically connected to a ground conductor (not shown). With this structure, impedance matching can be performed in the conductor 21b, suppressing signal transmission loss through the conductor 21b. Furthermore, the covering conductor 21c is not limited to a plate-like member; it can be a wire, mesh, or the like.

[0134] [Seventh Implementation]

[0135] Figure 9This is a side view showing the internal structure of the optical module 100G (100) of the seventh embodiment. The optical module 100G of this embodiment has the same structure as the optical module 100F of the sixth embodiment, except that a modulator driver 31 and a transimpedance amplifier 32 are provided outside the housing 10. In this embodiment, the same effects as in the sixth embodiment can also be obtained.

[0136] In this embodiment, the modulator driver 31 and the transimpedance amplifier 32, which serve as the heating element, are located outside the housing 10. With this structure, compared to a structure where the heating element is located inside the housing S (within the housing 10), the heat generated in the heating element is less likely to be transferred to the first device, which can further suppress the change in the characteristics of the light transmitted within the housing 10 due to the heating of the heating element, thereby suppressing the change in the optical characteristics of the optical module 100G.

[0137] Furthermore, a cavity 62G is provided in the feedthrough section 21E, at a location outside the housing 10. The cavity 62G is provided in the heat transfer path from the modulator driver 31 or transimpedance amplifier 32, which serves as a heat source, to the first device. It can suppress heat transfer from the heat source to the first device. Therefore, through the cavity 62G, it can also suppress the change in the characteristics of light transmitted within the housing 10 due to the heat generation of the heat source, thereby suppressing changes in the optical characteristics of the optical module 100G.

[0138] The above embodiments of the present invention are illustrative, but are merely examples and are not intended to limit the scope of the invention. The above embodiments can be implemented in various other forms, and various omissions, substitutions, combinations, and modifications can be made without departing from the spirit of the invention. Furthermore, the specifications of various structures, shapes, etc. (construction, type, orientation, form, size, length, width, thickness, height, quantity, configuration, position, material, etc.) can be appropriately modified for implementation.

[0139] For example, the cross-sectional shape of the cavity is not limited to a quadrilateral; it can also be an ellipse, a circle, a triangle, a trapezoid, a V-shape, or other shapes.

Claims

1. An optical module, characterized in that, have: The outer casing, which transmits light internally; Heating section; A device disposed within the housing, which, when heated, causes a change in the properties of light transmitted within the housing; and The first component is configured to contact the inner surface of the housing and be thermally connected to the heating element and the device. A heat transfer path is formed from the heating element through the first component and the housing to the device. In the first component, a cavity is provided along the heat transfer path from the heating element to the device, while suppressing convective heat transfer into the housing. As the cavity, a cavity is provided that extends from the first component toward the housing and opens to the outside of the housing, thereby suppressing heat transfer from the heating element to the device.

2. The optical module according to claim 1, characterized in that, The outer casing is airtight.

3. The optical module according to claim 1 or 2, characterized in that, In the first component, a cavity is provided as a closed space, which serves as the void.

4. The optical module according to claim 1 or 2, characterized in that, In the first component, a cavity is provided as the cavity, providing an opening into the outer shell. The optical module has the following features: A covered component that at least partially covers the opening.

5. The optical module according to claim 4, characterized in that, The covered component is at least one of a second component bonded to the first component and an adhesive that bonds the first component and the second component together.

6. The optical module according to claim 1 or 2, characterized in that, In the first component, as the cavity, a cavity is provided that is at least partially located within the outer shell.

7. The optical module according to claim 1 or 2, characterized in that, In the first component, a cavity is provided outside the outer shell as the cavity.

8. The optical module according to claim 1 or 2, characterized in that, The heating element and the device are arranged with a gap in the first direction. In the first component, as the voids, a plurality of voids spaced apart in the first direction are provided.

9. The optical module according to claim 1 or 2, characterized in that, The heating element and the device are arranged with a gap in the first direction. In the first component, as the voids, a plurality of voids are provided at intervals in a second direction that intersects the first direction.

10. The optical module according to claim 1 or 2, characterized in that, In the first component, as the cavity, a heat transfer layer with a higher thermal conductivity than the first component is provided on the inner surface of the cavity.

11. The optical module according to claim 1 or 2, characterized in that, The device comprises multiple components. In the first component, a cavity is provided as the cavity, which is located in the heat transfer path between the plurality of devices.

12. The optical module according to claim 1 or 2, characterized in that, The heating element is located within the outer casing.

13. The optical module according to claim 1 or 2, characterized in that, The heating element is located outside the outer casing.

14. The optical module according to claim 1 or 2, characterized in that, The heating element is equipped with a heating element that performs electrical operation.

15. The optical module according to claim 14, characterized in that, The heat-generating chip is flip-chip mounted on the first component.

16. The optical module according to claim 1 or 2, characterized in that, The optical module has the following features: A joint is a junction of multiple components that is heated during the joining process.

17. The optical module according to claim 16, characterized in that, The joint is located outside the housing. In the first component, a cavity is provided outside the outer shell as an enclosed space.

18. The optical module according to claim 1 or 2, characterized in that, The outer shell is the first component.

19. The optical module according to claim 1 or 2, characterized in that, As the first component, it includes a support component for supporting the device.

20. The optical module according to claim 19, characterized in that, As the first component, it has a fixing component that is fixed to the supporting component.

21. The optical module according to claim 1 or 2, characterized in that, The first component is made of a porous material.

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