Optical device

Abstract

To obtain an optical device which, for example, is formed at a lower cost and can secure required temperature control performance.SOLUTION: An optical device includes, for example, a temperature control device which has a first surface oriented in a first direction and a second surface oriented in a direction opposite to the first direction at the opposite side of the first surface and in which one of the first surface and the second surface serves as a heat absorption surface and the other surface serves as a heat radiation surface; an optical component provided on the first surface; and a cover which is located on the first surface, covers the optical component, and is made of a light transmissive synthetic resin material which transmits light received or sent by the optical component.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an optical device. [Background technology]

[0002] Conventionally, optical devices in which optical components are housed in a housing are known (Patent Document 1 and Patent Document 2). In Patent Document 1, the housing is made of a metal material, and in Patent Document 2, the housing is made of ceramic. In Patent Document 1, a temperature control device is also housed in the housing together with the optical components.

[0003] In optical devices having a housing made of metal or ceramic, as in Patent Documents 1 and 2, there is a problem in that, for example, the manufacturing cost of the housing is high, which in turn increases the manufacturing cost and price of the optical device.

[0004] On the other hand, an optical device in which optical components are covered with a synthetic resin material is known (Patent Document 3). In this case, the manufacturing cost and price of the optical device can be reduced compared to cases in which the housing is made of a metal material or ceramic. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2002-111115 A [Patent Document 2] Japanese Patent Application Publication No. 4-167583 [Patent Document 3] JP 2004-319555 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, when an optical device is equipped with a temperature control device as in Patent Document 1, if the temperature control device is entirely covered with a synthetic resin material, heat will be transferred between the high-temperature and low-temperature parts of the temperature control device via the synthetic resin material, reducing the temperature difference between the high-temperature and low-temperature parts, and there is a risk that the required temperature control function will not be obtained.

[0007] Therefore, one object of the present invention is to provide an optical device that can be constructed at lower cost and that can ensure a required temperature control performance, for example. [Means for solving the problem]

[0008] The optical device of the present invention, for example, has a first surface facing a first direction and a second surface opposite the first surface facing the opposite direction to the first direction, and is equipped with a temperature control device in which one of the first surface and the second surface serves as a heat absorption surface and the other surface serves as a heat dissipation surface, an optical component provided on the first surface, and a cover positioned on the first surface, covering the optical component and made of a light-transmitting synthetic resin material that transmits light received or transmitted by the optical component.

[0009] Also, in the optical device, for example, the temperature control device has a first substrate having the first surface, a second substrate having the second surface, and a thermoelectric element positioned between the first substrate and the second substrate, and the cover contacts only the first substrate among the first substrate, the second substrate, and the thermoelectric element.

[0010] In the optical device, for example, the cover partially covers the first surface.

[0011] The optical component further includes an electrically operable photoelectric component, and a conductor is provided at a portion of the first surface that is removed from the cover and is electrically connected to the photoelectric component and exposed from the cover.

[0012] The optical device may also include, for example, a temperature sensor covered by the cover.

[0013] In the optical device, for example, the outer surface of the cover is covered with a coating of an inorganic material.

[0014] In the optical device, for example, the coating is a metal film.

[0015] In the optical device, for example, the synthetic resin material is any one of an epoxy resin, an acrylic resin, and a silicone resin.

[0016] In addition, in the optical device, for example, the optical component is a semiconductor laser module.

[0017] The optical device also includes, for example, an optical fiber that is inserted into the cover and optically coupled to the optical component. Effect of the Invention

[0018] According to the present invention, for example, it is possible to obtain an optical device that can be constructed at lower cost and that can ensure a required temperature control performance. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is an exemplary schematic perspective view of an optical device according to an embodiment. [Diagram 2] FIG. 2 is an exemplary schematic side view of the optical device according to the embodiment, including a cross section of the cover taken along line II-II in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Exemplary embodiments of the present invention are disclosed below. The configurations of the embodiments shown below, and the actions and results (effects) brought about by the configurations are merely examples. The present invention can be realized by configurations other than those disclosed in the following embodiments. Furthermore, according to the present invention, it is possible to obtain at least one of the various effects (including derivative effects) obtained by the configurations.

[0021] In this specification, ordinal numbers are given for the sake of convenience to distinguish between parts, portions, etc., and do not indicate a priority order or sequence.

[0022] In each figure, the X direction is represented by an arrow X, the Y direction is represented by an arrow Y, and the Z direction is represented by an arrow Z. The X direction, Y direction, and Z direction intersect with each other and are perpendicular to each other. The X direction can also be called the longitudinal direction or extension direction, the Y direction can also be called the transverse direction or width direction, and the Z direction can also be called the height direction or thickness direction.

[0023] [Embodiment] Fig. 1 is a perspective view of an optical device 1 according to an embodiment, and Fig. 2 is a side view of the optical device 1, including a cross section of a cover 10 taken along line II-II in Fig. 1.

[0024] As shown in FIGS. 1 and 2, the optical device 1 includes a cover 10, a temperature adjustment device 20, a light emitting element 31, a lens 32, an optical fiber 33, a carrier , a support part 35, and a temperature sensor .

[0025] 1 and 2, the temperature adjustment device 20 has an upper substrate 21U, a lower substrate 21L, and a plurality of thermoelectric elements 22. The thermoelectric elements 22 are each interposed between the upper substrate 21U and the lower substrate 21L.

[0026] The upper substrate 21U extends across the Z direction. In this embodiment, the upper substrate 21U extends in the X direction and the Y direction and is perpendicular to the Z direction. The upper substrate 21U has an upper surface 20a facing the Z direction and a lower surface 21b on the back side of the upper surface 20a. The upper substrate 21U can be made of an insulating material with high thermal conductivity, such as ceramic. The upper substrate 21U is an example of a first substrate, and the upper surface 20a is an example of a first surface. The Z direction is an example of a first direction.

[0027] Optical components such as the light emitting element 31, lens 32, and optical fiber 33 are attached directly or indirectly via other components on the upper surface 20a. The upper substrate 21U may also be referred to as a mounting substrate, and the upper surface 20a may also be referred to as a mounting surface.

[0028] The lower substrate 21L extends across the Z direction on the opposite side to the upper substrate 21U. In this embodiment, the lower substrate 21L extends in the X direction and the Y direction and is perpendicular to the Z direction. The lower substrate 21L has an upper surface 21a and a lower surface 20b facing the opposite direction of the Z direction on the back side of the upper surface 21a. The lower substrate 21L may be made of an insulating material with high thermal conductivity, such as ceramic. The lower substrate 21L is an example of a second substrate and may also be referred to as a mounting substrate. The lower surface 20b is an example of a second surface and may also be referred to as a mounting surface.

[0029] The thermoelectric element 22 may be made of a P-type or N-type semiconductor, such as, for example, a bismuth telluride based semiconductor.

[0030] A wiring pattern (not shown) is provided on the lower surface 21b of the upper substrate 21U and the upper surface 21a of the lower substrate 21L. The thermoelectric elements 22 are respectively interposed between these two wiring patterns. The wiring pattern can be made of a highly conductive metal material, such as a copper-based metal.

[0031] The general portions (insulating portions) of the upper substrate 21U and the lower substrate 21L may be made of, for example, low temperature co-fired ceramics (LTCC) or ceramic.

[0032] The thermoelectric elements 22 are connected in series to form a PN junction via the wiring pattern. The thermoelectric elements 22 generate or absorb heat when power is supplied from outside the temperature adjustment device 20 via the wiring pattern. The thermoelectric elements 22 generate and absorb heat depending on the direction of the current flowing through the thermoelectric elements 22. The wiring pattern may also be referred to as a conductor or a conductor layer.

[0033] In the temperature adjustment device 20, one of the upper surface 20a and the lower surface 20b becomes a heat absorption surface and the other becomes a heat dissipation surface. That is, in the temperature adjustment device 20, depending on the direction of the current, a state in which the upper surface 20a becomes a heat absorption surface and the lower surface 20b becomes a heat dissipation surface and a state in which the upper surface 20a becomes a heat dissipation surface and the lower surface 20b becomes a heat absorption surface are switched.

[0034] In this way, the temperature adjustment device 20 functions as a base for the optical components, and adjusts the temperature of the optical components by heating or cooling the optical components. The temperature adjustment device 20 may also be called a Peltier module or a thermoelectric module.

[0035] The light-emitting element 31, which is an optical functional element, is, for example, a semiconductor laser module, and one example is a wavelength-tunable laser element. The light-emitting element 31 is mounted on the upper surface 20a of the temperature adjustment device 20 via a carrier 34. The light-emitting element 31 is an example of a photoelectric component driven by an electric signal.

[0036] The carrier 34 is made of an insulating material with high thermal conductivity, and transfers heat generated by the light emitting element 31 to the temperature adjustment device 20. The carrier 34 may also be called a submount.

[0037] The light emitting element 31 outputs a laser beam toward the lens 32. The wavelength of the laser beam is, for example, 900 nm or more and 1650 nm or less, which is a suitable wavelength for optical communication. The element temperature of the light emitting element 31 increases while the laser beam is being output, and the light emitting element 31 functions as a heating element.

[0038] The lens 32 collimates the laser light from the light-emitting element 31 by applying a refractive index effect. The laser light output from the lens 32 is input to an end of an optical fiber 33 supported by a support part 35. The optical fiber 33 is optically coupled to the light-emitting element 31 and the lens 32.

[0039] The temperature sensor 36 detects the temperature of a predetermined portion. The temperature sensor 36 is, for example, a thermistor. The temperature sensor 36 detects, for example, the ambient temperature of the light-emitting element 31. In this case, the detected temperature is used to control the temperature adjustment device 20 for adjusting the temperature of the light-emitting element 31.

[0040] 1 and 2, the cover 10 partially covers the upper surface 20a of the upper substrate 21U. The cover 10 is made of a synthetic resin material such as epoxy resin, acrylic resin, or silicone resin. The cover 10 is poured in a fluid state onto the upper surface 20a of the upper substrate 21U of the temperature adjustment device 20 set in a mold, and is solidified by cooling, heating, or ultraviolet light irradiation.

[0041] The cover 10 is in contact with only the upper substrate 21U among the upper substrate 21U, the lower substrate 21L, and the thermoelectric element 22. In this embodiment, the cover 10 is positioned in the Z direction with respect to the upper surface 20a of the upper substrate 21U.

[0042] 2, the cover 10 placed on the upper surface 20a entirely covers the components provided on the upper surface 20a, that is, in this embodiment, the light emitting element 31, the lens 32, the optical fiber 33, the carrier 34, the support component 35, and the temperature sensor 36. These components are embedded in the cover 10 and are physically protected by the cover 10. The optical fiber 33 is inserted in the cover 10. The cover 10 may also be referred to as a sealing resin or a molding resin.

[0043] The cover 10 is made of a synthetic resin material having optical transparency that transmits the light emitted by the light-emitting element 31. When the optical device 1 has a light-receiving element as an optical component, the cover 10 is made of a synthetic resin material having optical transparency that transmits the light received by the light-receiving element.

[0044] The conductor 21c is exposed at a portion of the upper surface 20a that is not covered by the cover 10, that is, at a portion that is exposed and not covered by the cover 10. In other words, the conductor 21c that is exposed from the cover 10 is provided on the upper surface 20a.

[0045] The conductor 21c is electrically connected to a connection conductor provided on the upper substrate 21U, for example, a connection conductor (not shown) provided on the upper surface 20a or in the upper substrate 21U. Furthermore, the connection conductor is electrically connected to (the internal conductor of) the light-emitting element 31 as a photoelectric component and (the internal conductor of) the temperature sensor 36. That is, the conductor 21c includes the conductor 21c electrically connected to the light-emitting element 31 as a photoelectric component through the connection conductor and the conductor 21c electrically connected to the temperature sensor 36 through the connection conductor. The conductor 21c is used for electrical connection between an external device different from the optical device 1 and a conductor of the external device. The conductor 21c is, for example, a pad, and may also be called an electrode or a terminal. The connection conductor is, for example, a wiring pattern, a via, a bonding wire, or the like, and may also be called wiring. The temperature sensor 36 may also be called an electric component or a thermoelectric component. Note that the lower substrate 21L may also be provided with a conductor 21d electrically connected to the connection conductor like the conductor 21c.

[0046] Conductor portions provided on upper substrate 21U and lower substrate 21L, such as conductor 21c, connecting conductors, and wiring patterns, are made of a highly conductive metal material, such as a copper-based material.

[0047] With the above-described structure, the cover 10 prevents liquid from acting on the components located on the upper surface 20a, i.e., in this embodiment, the light-emitting element 31, the lens 32, the optical fiber 33, the carrier 34, the support part 35, and the temperature sensor 36.

[0048] The outer surface 10a of the cover 10 is covered with a coating 40 made of an inorganic material. The coating 40 can be made of an aluminum-based metal material, such as aluminum, aluminum oxide, or an aluminum alloy. The coating 40 may also be made of a non-metallic material, such as diamond-like carbon. The coating 40 prevents the gas from acting on the components located on the upper surface 20a, that is, in this embodiment, the light-emitting element 31, the lens 32, the optical fiber 33, the carrier 34, the support component 35, and the temperature sensor 36.

[0049] Through extensive research, the inventors have confirmed that when coating 40 is made of a metallic material or diamond-like carbon, if the thickness of coating 40 is 0.1 μm or greater, it is possible to guarantee gas barrier properties that prevent leakage of helium gas at a specified pressure, i.e., gas barrier properties that ensure the reliability of optical components.

[0050] As described above, in this embodiment, the optical device 1 includes the temperature adjustment device 20, components including optical components such as the light emitting element 31 provided on the upper surface 20a (first surface) of the temperature adjustment device 20, and the cover 10 that covers the components. The cover 10 is made of a light-transmitting synthetic resin material that transmits light received or transmitted by the optical components.

[0051] According to such a configuration, for example, the optical device 1 is provided with the cover 10 made of a synthetic resin material, and does not include a housing made of a metal material or ceramic, so that it is possible to manufacture the optical device 1 more inexpensively. Furthermore, since the cover 10 is made of a light-transmitting synthetic resin material, even if the cover 10 is interposed between multiple optical components, optical coupling between the multiple optical components can be ensured.

[0052] In this embodiment, for example, of the upper substrate 21U (first substrate), the lower substrate 21L (second substrate), and the thermoelectric element 22 of the temperature adjustment device 20, the cover 10 is in contact with only the upper substrate 21U.

[0053] With this configuration, for example, it is possible to avoid a situation where the cover 10 straddles the upper substrate 21U and the lower substrate 21L, and heat is transferred between the upper substrate 21U and the lower substrate 21L by the straddled portion, which in turn makes it difficult to ensure the temperature control performance of the temperature control device 20. Therefore, with this configuration, it is possible to more reliably obtain the required temperature control performance of the temperature control device 20. Furthermore, when the cover 10 is interposed between the optical component and the upper substrate 21U, it is possible to ensure a heat transfer path from the optical component to only the upper substrate 21U via the cover 10.

[0054] In this embodiment, for example, the cover 10 partially covers the upper surface 20a (first surface).

[0055] According to such a configuration, for example, the amount of cover 10 can be reduced compared to when cover 10 covers the entire upper surface 20a, which has the advantage that the optical device 1 can be manufactured more cheaply and more lightweight.

[0056] In addition, in this embodiment, for example, a conductor 21c exposed from the cover 10 is provided in a portion of the upper surface 20a that is not covered by the cover 10, and the conductor 21c is electrically connected to a photoelectric component such as a light-emitting element 31.

[0057] According to such a configuration, for example, the conductor 21c can be configured to electrically connect an external device other than the optical device 1 or an external device to a photoelectric component with a relatively simple configuration.

[0058] In this embodiment, for example, the optical device 1 includes a temperature sensor 36 covered by the cover 10.

[0059] With such a configuration, for example, the temperature of each part inside the cover 10 can be detected.

[0060] In this embodiment, for example, the outer surface 10a of the cover 10 is covered with a coating 40 made of an inorganic material.

[0061] With this configuration, even if it is difficult to ensure gas barrier properties, for example, in the cover 10 made of a synthetic resin material, the required gas barrier properties can be ensured by the coating 40. In other words, a configuration that protects the components from liquids and gases while providing physical protection at a lower cost can be realized with a relatively inexpensive and simple configuration.

[0062] Although the embodiment of the present invention has been illustrated above, the above embodiment is merely an example and is not intended to limit the scope of the invention. The above embodiment can be implemented in various other forms, and various omissions, substitutions, combinations, and modifications can be made without departing from the gist of the invention. In addition, the specifications of each configuration, shape, and the like (structure, type, direction, model, size, length, width, thickness, height, number, arrangement, position, material, etc.) can be appropriately changed and implemented.

[0063] For example, the optical device may include other components covered by a cover, other optical components, or other photoelectric components. The optical device may be a device other than a semiconductor laser module. The layout of these components is not limited to the above embodiment.

[0064] For example, the first coating, the second coating, and the third coating may each be a so-called multilayer film in which multiple films are stacked, and in this case, may include films (layers) made of different materials, such as a diamond-like carbon film and an aluminum film. [Explanation of symbols]

[0065] 1...Optical device 10…Cover 10a…Outer surface 20…Temperature control device 20a...Top surface (first surface) 20b…Bottom surface 21a…Top surface 21b…Bottom surface 21c…conductor 21d…Conductor 21U...Upper board (first board) 21L...Lower board (second board) 22...Thermoelectric element 31...Light emitting element (optical component, photoelectric component) 32...Lens (optical component) 33...Optical fiber (optical components) 34…Career 35…Support parts 36...Temperature sensor 40...Coating X…direction Y...Direction Z…direction (first direction)

Claims

1. a temperature control device having a first surface facing a first direction and a second surface facing a direction opposite to the first direction on the opposite side of the first surface, one of the first surface and the second surface being a heat absorption surface and the other surface being a heat radiation surface; An optical component provided on the first surface; a cover positioned on the first surface, covering the optical component, and made of a light-transmitting synthetic resin material that transmits light received or transmitted by the optical component; An optical device comprising: the cover partially covers the first surface; the optical component includes an electrically actuable photoelectric component; a conductor electrically connected to the photoelectric component and exposed from the cover is provided at a portion of the first surface that is not exposed from the cover; the conductor is electrically connected to a conductor of an external device or an external apparatus different from the optical device; the temperature control device includes a first substrate having the first surface, a second substrate having the second surface, and a thermoelectric element positioned between the first substrate and the second substrate; the cover covers a portion of the first surface without contacting the second substrate and the thermoelectric element; an optical device comprising a temperature sensor covered by the cover, the detected temperature of which is used to control the temperature adjustment device for adjusting the temperature of the optical component;

2. The optical device of claim 1 , wherein an outer surface of the cover is covered with a coating of an inorganic material.

3. The optical device of claim 2 , wherein the coating is a metal film.

4. a temperature control device having a first surface facing a first direction and a second surface facing a direction opposite to the first direction on the opposite side of the first surface, one of the first surface and the second surface being a heat absorption surface and the other surface being a heat radiation surface; An optical component provided on the first surface; a cover positioned on the first surface, covering the optical component, and made of a light-transmitting synthetic resin material that transmits light received or transmitted by the optical component; Equipped with The outer surface of the cover is covered with a coating made of a non-metallic material having gas barrier properties, the temperature control device includes a first substrate having the first surface, a second substrate having the second surface, and a thermoelectric element positioned between the first substrate and the second substrate; the cover covers a portion of the first surface without contacting the second substrate and the thermoelectric element; an optical device comprising a temperature sensor covered by the cover, the detected temperature of which is used to control the temperature adjustment device for adjusting the temperature of the optical component;

5. the optical component includes an electrically actuable photoelectric component; The optical device according to claim 4 , wherein a conductor is provided on a portion of the first surface that is not covered by the cover, the conductor being electrically connected to the photoelectric component and exposed from the cover.

6. 6. The optical device according to claim 1, wherein the synthetic resin material is any one of an epoxy resin, an acrylic resin, and a silicone resin.

7. 7. The optical device according to claim 1, wherein the optical component is a semiconductor laser module.

8. 8. The optical device according to claim 1, further comprising an optical fiber inserted in the cover and optically coupled to the optical component.

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