Optical module

Abstract

For example, the present invention provides an improved novel optical module that can suppress excessive temperature rise associated with the operation of the drive element. [Solution] The optical module comprises, for example, an optical modulation element having an optical modulation section having a waveguide extending in a first direction, a drive element having a drive circuit for driving the optical modulation section, a base on which the optical modulation element and the drive element are mounted, having a first surface substantially aligned with the first direction and substantially aligned with a second direction intersecting the first direction, an insulator, and a conductor. The optical modulation element is provided on the first surface, the drive element is spaced apart from the optical modulation element in the second direction, and a heat dissipation section is provided on the base in a third direction aligned with the drive element in both the first and second directions. The heat dissipation section may be a conductor at ground potential.

Description

Technical Field

[0001] The present invention relates to an optical module.

Background Art

[0002] Conventionally, an optical module having a plurality of optical modulation units and a driving element (driver) for driving the plurality of optical modulation units has been known (Patent Document 1).

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In this type of optical module, it is not preferable that an excessive temperature rise occurs in the driving element and thus in the optical module due to the operation of the driving element.

[0005] Therefore, one of the problems of the present invention is to provide an improved and novel optical module capable of suppressing, for example, an excessive temperature rise associated with the operation of a driving element.

Means for Solving the Problems

[0006] The optical module of the present invention includes, for example, an optical modulation element having an optical modulation unit with a waveguide extending in a first direction, a driving element having a driving circuit for driving the optical modulation unit, a first surface substantially along the first direction and substantially along a second direction intersecting the first direction, an insulator, and a conductor, and a base on which the optical modulation element and the driving element are mounted. The optical modulation element is provided on the first surface, the driving element is spaced apart from the optical modulation element in the second direction, and a heat radiating portion is provided at a portion of the base that is arranged in a third direction intersecting the first direction and the second direction with respect to the driving element.

[0007] In the optical module, the optical modulation element may include a first optical modulation section having a first waveguide as the waveguide, and a second optical modulation section having a second waveguide as the waveguide, which is spaced apart from the first waveguide in the second direction and substantially parallel to the first waveguide, and the driving element may include a driving element having a first driving circuit as the driving circuit for driving the first optical modulation section and a second driving circuit as the driving circuit for driving the second optical modulation section.

[0008] In the optical module described above, the heat dissipation section may be the conductor that is at ground potential.

[0009] In the optical module, the base has a second surface that faces in the opposite direction to the first surface and intersects with the first direction, and the driving element may be provided on the second surface.

[0010] In the optical module, the driving element has a pair of first output terminals that output a differential electrical signal, the first optical modulation unit has a pair of first electrodes to which the differential electrical signal is input, and the base has a pair of first differential wirings as conductors that pass through a position separated from the first surface in the opposite direction to the third direction and electrically connect the pair of first output terminals and the pair of first electrodes, respectively, and the first differential wirings may be provided exposed on the second surface.

[0011] In the optical module, the driving element has a pair of first output terminals that output a differential electrical signal, the first optical modulation unit has a pair of first electrodes to which the differential electrical signal is input, and the base has a pair of first differential wirings that, as conductors, pass through a position separated from the first surface in the opposite direction to the third direction and electrically connect the pair of first output terminals and the pair of first electrodes, respectively, and the first differential wirings may be provided on the second surface and covered with a coating layer made of a material with a lower dielectric constant than the base. [Effects of the Invention]

[0012] According to the present invention, for example, it is possible to provide an improved novel optical module that can suppress excessive temperature rise associated with the operation of the driving element. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is an exemplary and schematic perspective view of an optical module according to the first embodiment. [Figure 2] Figure 2 is an illustrative and schematic plan view of the optical module of the first embodiment. [Figure 3] Figure 3 is a plan view of part III of Figure 2. [Figure 4] Figure 4 is an illustrative and schematic plan view of a portion of the optical module of the first embodiment, viewed from a different direction than that shown in Figure 2. [Figure 5] Figure 5 is a cross-sectional view of the VV section of Figure 1. [Modes for carrying out the invention]

[0014] The following describes exemplary embodiments of the present invention. The configurations of the embodiments shown below, as well as the actions and results (effects) brought about by such configurations, are examples only. The present invention can also 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 derived effects) that can be obtained by the configuration.

[0015] The multiple embodiments shown below have similar configurations. Therefore, according to the configuration of each embodiment, similar functions and effects based on the same configuration can be obtained. In addition, similar components are given the same reference numerals below, and redundant explanations may be omitted.

[0016] Furthermore, in this specification, ordinal numbers may be assigned for convenience to distinguish parts, components, sections, directions, light, etc. However, ordinal numbers do not indicate priority or order, nor do they specify a number.

[0017] In addition, in each figure, the X direction is represented by arrow X, the Y direction is represented by arrow Y, and the Z direction is represented by arrow Z. The X direction, Y direction, and Z direction intersect each other and are orthogonal to each other. Note that each figure is schematic, and the shape, dimensions, etc. of each part may be different from the actual ones.

[0018] [First Embodiment] [Overview of Optical Module] FIG. 1 is a perspective view of an optical module 100A (100) according to the first embodiment. Further, FIG. 2 is a plan view of the optical module 100A as viewed from the lower surface 11b opposite to the upper surface 11a shown in FIG. 1.

[0019] As shown in FIGS. 1 and 2, the optical module 100A includes a base 10A (10), an optical modulation element 20, a driving element 30, and a wiring member 40. The optical modulation element 20 and the driving element 30 are mounted on the base 10A.

[0020] The base 10A has an insulator 11 and a conductor 12. The insulator 11 is made of a material with high thermal conductivity and insulation, such as a ceramic material, for example. Specifically, the insulator 11 is made of aluminum nitride, for example. The conductor 12 is made of a material with high thermal conductivity and conductivity, such as a copper-based metal material, for example. The base 10A has a multilayer substrate structure.

[0021] The insulator 11 has a thin, flat rectangular parallelepiped shape in the Z direction, has a substantially constant width in the Y direction, and extends in the X direction. The insulator 11 is provided with recesses 11d and 11e. Except for the portions where the recesses 11d and 11e are provided, the height of the insulator 11 in the Z direction is substantially constant.

[0022] The insulator 11 has an upper surface 11a, a lower surface 11b, and four side surfaces 11c. The upper surface 11a intersects the Z direction and faces in the opposite direction to the Z direction. The lower surface 11b intersects the Z direction and faces in the Z direction. The side surfaces 11c each extend substantially along the Z direction and face either the X direction or the Y direction.

[0023] As shown in Figure 1, the upper surface 11a is provided with a rectangular recess 11d that opens in a plan view when viewed in the Z direction, having sides aligned with the X direction and sides aligned with the Y direction. The bottom surface 11d1 of the recess 11d intersects with the Z direction and faces in the opposite direction to the Z direction.

[0024] Furthermore, as shown in Figure 2, the lower surface 11b is provided with a recess 11e extending in the X direction with a predetermined depth in the Z direction and a predetermined width in the Y direction. The bottom surface 11e1 of the recess 11e is substantially aligned with the X and Y directions, intersects with the Z direction, and faces the Z direction. The recess 11e has a section extending in the X direction with a substantially constant depth in the Z direction and a substantially constant width in the Y direction, approximately in the center of the X direction. The optical modulation element 20 is housed in this section. In this section, the optical modulation element 20 is provided on the bottom surface 11e1. The Z direction is an example of a third direction, and the bottom surface 11e1 is an example of a first surface. Furthermore, stepped surfaces 11f are provided on both sides of this section in the Y direction. The stepped surfaces 11f intersect with the Z direction and face the Z direction. The stepped surfaces 11f are located between the bottom surface 11e1 and the lower surface 11b in the Z direction.

[0025] Furthermore, wide sections are provided on both sides of the recess 11e in the X direction with respect to the section in which the optical modulation element 20 is housed. These wide sections house a support portion (not shown) that supports optical fibers (not shown) that are optically connected to the waveguides 211 and 212 of the optical modulation element 20. This support portion is fixed to the base 10A.

[0026] Furthermore, the recess 11e may be covered with a lid member 14. The lid member 14 may be made of, for example, glass. With this configuration, the chamber enclosed by the recess 11e and the lid member 14 can be airtightly sealed by bonding the lid member 14 to the periphery of the recess 11e with an adhesive. In this case, an inert gas, such as nitrogen gas, may be sealed inside the chamber.

[0027] [Optical Modulator] The optical modulation element 20 includes a first optical modulation unit 201 that performs optical modulation in a waveguide 211, and a second optical modulation unit 202 that performs optical modulation in a waveguide 212. The first optical modulation unit 201 and the second optical modulation unit 202 are, for example, semiconductor optical modulators such as InP optical modulators or LN modulators. In this embodiment, both the first optical modulation unit 201 and the second optical modulation unit 202 are phase modulators, but the embodiment is not limited to this, and may be intensity modulators or optical modulators having a Mach-Zehnder type waveguide.

[0028] Waveguides 211 and 212 both extend in the X direction and are parallel to each other in the sections that constitute the first optical modulation section 201 and the second optical modulation section 202 in close proximity to at least one pair of electrodes 231 and 232. Waveguide 212 is separated from waveguide 211 in the Y direction. Waveguide 211 is an example of the first waveguide, and waveguide 212 is an example of the second waveguide. The X direction is an example of the first direction, and the Y direction is an example of the second direction.

[0029] Furthermore, the optical modulation element 20 has a rectangular parallelepiped shape that extends long in the X direction, with a substantially constant height in the Z direction and a substantially constant width in the Y direction, extending in the X direction.

[0030] Figure 3 is a plan view of the optical module 100 in section III of Figure 2. As shown in Figures 2 and 3, the optical modulation element 20 is located approximately in the center of the optical modulation element 20 in the Y direction and has a symmetrical configuration with respect to a virtual plane VP that intersects the Y direction. This configuration makes it possible to suppress characteristic differences between the first optical modulation section 201 and the second optical modulation section 202 that are due to their configuration.

[0031] The optical modulation element 20 also includes a main body 220, waveguides 211 and 212, a pair of electrodes 231 and a pair of electrodes 232. The main body 220 has a substantially rectangular parallelepiped shape and has a surface 20a at its Z-direction end that intersects with the Z-direction. The waveguides 211 and 212 are formed within the main body 220 at positions closer to surface 20a than, for example, surface 20b (see Figure 5) opposite surface 20a. The electrodes 231 and 232 are each provided on surface 20a, sandwiching the corresponding waveguides 211 and 212 at a certain distance when viewed in the opposite direction of the Z-direction. The waveguides 211 and 212 extend in the X-direction and are parallel to each other, at least in the sections adjacent to the corresponding electrodes 231 and 232. The electrodes 231 and 232 are made of a conductive material, such as a copper-based metal material.

[0032] The ends 231a of the two electrodes 231 are electrically connected to the conductor wiring 12D1(12) provided on the stepped surface 11f of the insulator 11 via bonding wires 13. The ends 232a of the two electrodes 232 are electrically connected to the conductor wiring 12D2(12) provided on the stepped surface 11f of the insulator 11 via bonding wires 13. Furthermore, terminals 231b and 232b, which are at ground potential, are provided on the surface 20a, and these terminals 231b and 232b are electrically connected to the ground wiring 12G(12) provided on the stepped surface 11f via bonding wires 13. At the opposite edge of the surface 20a in the Y direction, terminal 231b, end 231a, another end 211a, and another terminal 231b are arranged in the X direction with spacing between them in this order. On the other hand, at the Y-direction edge of surface 20a, terminal 232b, end 232a, another end 232a, and another terminal 232b are arranged in the X-direction with spacing between them in this order. In this configuration, the ends of the two electrodes 231 opposite to end 231a are both electrically connected to the termination resistor 234 shown in Figure 2 via a bonding wire (not shown). Similarly, the ends of the two electrodes 232 opposite to end 232a are both electrically connected to the termination resistor 234 shown in Figure 2 via a bonding wire (not shown).

[0033] [Driver elements and conductor wiring] Figure 4 is a plan view of the portion of the optical module 100A where the recess 11d is provided, viewed in the Z direction. A drive element 30 is mounted on the bottom surface 11d1 of the recess 11d. The drive element 30 has a drive circuit for driving the first optical modulation unit 201 and a drive circuit for driving the second optical modulation unit 202. The output terminal 30b1 of the drive circuit for driving the first optical modulation unit 201 is electrically connected to the conductor wiring 12D1 provided on the bottom surface 11d1. The output terminal 30b2 of the drive circuit for driving the second optical modulation unit 202 is electrically connected to the conductor wiring 12D2 provided on the bottom surface 11d1. In addition, the internal wiring of the drive element 30 is electrically connected to the conductor wiring 12I(12) and the conductor 42 of the wiring member 40 via other electrodes. In this embodiment, the wiring member 40 is, for example, a flexible printed circuit board having an insulating layer 41 and a conductor 42, but it is not limited to this, and may be other flexible wiring or a rigid wiring board, for example.

[0034] Figure 5 is a cross-sectional view of VV in Figure 1. As shown in Figure 5, in the base 10A, the conductor 12 has conductor wirings 12D1, 12D2, and 12I that constitute the signal wiring, and a ground wiring 12G that is at ground potential. The base 10A is also configured as a multilayer substrate in which layers of insulator 11 and layers of conductor 12 are laminated. In this configuration, the conductor 12 is configured as a thin film-like strip conductor 12a (wiring pattern, see Figure 4) intersecting the Z direction, a solid or hollow via 12b extending in the Z direction, a layered conductor 12c intersecting the Z direction, etc. The strip conductor 12a is formed in a straight or bent strip shape, as shown in the conductor wirings 12D1, 12D2, and 12I in Figure 4. The via 12b penetrates each layer of insulator 11. Furthermore, the layered conductor 12c includes localized patterns 12c1, which are mainly provided around vias 12b as shown in Figure 5, and patterns 12c2 (solid patterns) that extend over a relatively wide area. Localized patterns 12c1 may constitute part of vias 12b. The Z direction may also be referred to as the thickness direction or lamination direction of the base 10A.

[0035] As shown in Figures 3-5, the pair of output terminals 30b1 of the drive element 30 are electrically connected to the pair of electrodes 231 via a pair of conductor wires 12D1 and bonding wires 13. The pair of conductor wires 12D1 extend between the drive element 30 and the pair of electrodes 231, maintaining a substantially constant distance from each other in each section, and constitute differential wiring that supplies differential electrical signals from the drive element 30 to the pair of electrodes 231. In addition, the pair of output terminals 30b2 of the drive element 30 are electrically connected to one electrode 232 via a pair of conductor wires 12D2 and bonding wires 13. The pair of conductor wires 12D2 extend between the drive element 30 and the pair of electrodes 232, maintaining a substantially constant distance from each other in each section, and constitute differential wiring that supplies differential electrical signals from the drive element 30 to the pair of electrodes 232.

[0036] Here, as shown in Figure 4, the waveguide 212 of the second optical modulation unit 202 is separated in the Y direction from the waveguide 211 of the first optical modulation unit 201, and the driving element 30 is separated in the Y direction from the waveguide 212. That is, the driving element 30 is separated in the Y direction from the optical modulation element 20. Also, as shown in Figure 3, a differential electrical signal is supplied to the pair of electrodes 231 of the first optical modulation unit 201 via a bonding wire 13 from a pair of conductor wirings 12D1 on a stepped surface 11f adjacent to the optical modulation element 20 in the opposite direction in the Y direction. Therefore, as shown in Figure 4, the pair of conductor wirings 12D1 that supply the differential electrical signal from the driving element 30 to the pair of electrodes 231 extend so as to straddle the two waveguides 211 and 212 in the Y direction.

[0037] In this embodiment, the pair of conductor wirings 12D1 straddle the two waveguides 211 and 212 in the Y direction on the bottom surface 11d1. That is, the pair of conductor wirings 12D1 straddle the two waveguides 211 and 212 in the Y direction at a position separated from the bottom surface 11e1 on which the driving element 30 is provided in the opposite direction in the Z direction. With this configuration, a part of the insulator 11 and a part of the main body 220 of the optical modulation element 20 are interposed between the waveguides 211 and 212 and the pair of conductor wirings 12D1. With this configuration, it is possible to suppress noise generated in the optical signals of waveguides 211 and 212 by electrical signals passing through the section of the pair of conductor wirings 12D1 that straddles waveguides 211 and 212.

[0038] Furthermore, a drive element 30 is mounted on the bottom surface 11d1 on which a pair of conductor wirings 12D1 are provided. The bottom surface 11d1 is an example of a second surface. Accordingly, the pair of conductor wirings 12D1 travel from the drive element 30, across the bottom surface 11d1, through vias 12b provided on the opposite side of the optical modulation element 20 from the drive element 30, to the stepped surface 11f, and then to the pair of electrodes 231 via bonding wires 13. Now, let's consider the case where the drive element 30 is mounted not on the bottom surface 11d1 which faces the opposite direction in the Z direction, but on a surface facing the Z direction, such as the stepped surface 11f or the bottom surface 11b. In this case, the pair of conductor wirings 12D1 provided so as to straddle the drive element 30 in the Y direction must each pass through two vias 12b that penetrate the insulator 11 in the thickness direction (Z direction) between the drive element 30 and the pair of electrodes 231. As described above, in this embodiment, the insulator 11 is made of a ceramic material such as aluminum nitride to ensure higher thermal conductivity. Furthermore, since the base 10A is a multilayer substrate, interlayer displacement (displacement in a direction intersecting the Z direction) and steps occur between the penetration portion of the insulating layer and the layered portion between the insulating layers at the via 12b. Due to these, in the conductor wiring 12D1, a decrease in impedance (mismatch) occurs at the via 12b, causing the via 12b to become a reflection point. In other words, in this configuration, since each conductor wiring 12D1 has two vias 12b, there are two reflection points for electrical signals in the conductor wiring 12D1. When there are two reflection points in a signal transmission path, the reflected wave is superimposed on the main signal, causing significant distortion of the signal waveform and potentially leading to a decrease in the eye aperture ratio in differential signals, i.e., a decrease in transmission characteristics. In this embodiment, the driving element 30 is provided on the bottom surface 11d1 (second surface), and the driving element 30 is provided on the bottom surface 11e1 (first surface) which faces in the opposite direction to the bottom surface 11d1. Therefore, the pair of conductor wirings 12D1 only need to pass through one via 12b. With this configuration, the degradation of transmission characteristics can be suppressed compared to the case where it passes through two vias 12b.

[0039] Furthermore, the pair of conductor wirings 12D1 and the pair of conductor wirings 12D2 are each provided exposed on the bottom surface 11d1. With this configuration, the pair of conductor wirings 12D1 become a microstrip line on the bottom surface 11d1, thereby improving the electrical signal transmission characteristics. The pair of conductor wirings 12D1 and the pair of conductor wirings 12D2 may be covered on the bottom surface 12d1 with a coating layer having a lower dielectric constant than the insulator 11 (for example, polyimide resin). With this configuration, the protection of the conductor wirings 12D1 and 12D2 can be improved. In this case as well, the electrical signal transmission characteristics can be improved compared to the case where the pair of conductor wirings 12D1 and the pair of conductor wirings 12D2 pass through the insulator 11.

[0040] Furthermore, as shown in Figure 4, in this embodiment, the strip-shaped conductor 12a of the pair of conductor wirings 12D1 includes a gently crank-shaped bend 12d on the bottom surface 11d1, which includes a portion that is inclined obliquely with respect to the Y direction. By providing this bend 12d, the position of the output terminal 30b1 of the drive element 30 and the end 12e of the conductor wiring 12D1 on the bottom surface 11d1 opposite to the drive element 30 are offset in the X direction. With this configuration, as shown in Figure 3, the position where the end 231a of the pair of electrodes 231 faces the pair of conductor wirings 12D1 and the position where the end 232a of the pair of electrodes 232 faces the pair of conductor wirings 12D2 can be aligned in the X direction.

[0041] When such a bent portion 12d is present, common-mode conversion of the signal transmission may occur, potentially leading to noise superimposition on the electrical signal. However, as described above, since the conductor wiring 12D1 constitutes a microstrip line in the portion where the bent portion 12d is provided, the effects of common-mode conversion can be suppressed. In this configuration, it has been found that the absolute value of the angle difference θ with respect to the Y direction of the inclined portion of the bent portion 12d is preferably, for example, 0° or more and 60° or less. Alternatively, a pair of conductor wirings 12D1 may be extended linearly along the Y direction, and a bent portion 12d may be provided in the pair of conductor wirings 12D2. However, in that case, the length of the pair of conductor wirings 12D will be increased by the amount of the bent portion 12d, forcing the drive element 30 to be placed further away from the waveguide 212. This may result in constraints on the layout of the drive element 30 and may suppress miniaturization of the optical module 100A in the Y direction. From this perspective, it is preferable that the bent portion 12d be provided on a pair of conductor wires 12D1 that is longer in length than the pair of conductor wires 12D2 on the bottom surface 12d1.

[0042] Furthermore, as shown in Figure 5, in this embodiment, multiple vias 12b of the ground wiring 12G are provided on the base 10A in a portion adjacent to the drive element 30 in the Z direction, in other words, in a portion aligned with the drive element 30 in the Z direction. These vias 12b are thermally connected to the drive element 30 and serve as a heat dissipation path for the heat generated by the drive element 30. This configuration makes it possible to suppress the drive element 30 from becoming excessively hot. In addition, by using the vias 12b of the ground wiring 12G as a heat dissipation path, advantages such as being able to make the optical module 100 more compact and reducing manufacturing effort and cost can be obtained compared to when a separate heat dissipation path is provided. Furthermore, in this configuration, it is preferable that at least a portion of the vias 12b of the ground wiring 12G are exposed on the lower surface 11b. In that case, the heat dissipation performance by the vias 12b of the ground wiring 12G can be further improved. The vias 12b of the ground wiring 12G are an example of a heat dissipation part and an example of a conductor that becomes ground potential.

[0043] As explained above, in this embodiment, heat can be dissipated from the drive element 30 through the via 12b of the ground wiring 12G, which acts as a heat dissipation section, thus suppressing an excessive temperature rise of the drive element 30. Furthermore, in this embodiment, the optical modulation element 20 and the drive element 30 are offset from each other in the Y direction (second direction) and do not overlap in the Z direction (third direction). Therefore, the optical modulation element 20 does not obstruct the layout of the via 12b of the ground wiring 12G, and a configuration in which the drive element 30 and the via 12b of the ground wiring 12G are aligned in the Z direction can be realized relatively easily. In addition, because the optical modulation element 20 and the via 12b of the ground wiring 12G can be offset in the Y direction, it is possible to suppress the adverse effects of heat generated in the drive element 30 on the optical modulation element 20.

[0044] Furthermore, in this embodiment, an optical module 100A (100) can be configured such that the first optical modulation section 201 and the second optical modulation section 202 (multiple optical modulation sections) and the driving element 30 are not aligned in the X direction (first direction, longitudinal direction) of the waveguides 211, 212. Therefore, it is possible to suppress the length of the optical module 100 in the X direction, making it easier to apply the optical module 100 in situations where there are length constraints in the X direction at the application location of the optical module 100.

[0045] Although embodiments and modifications of the present invention have been illustrated above, these embodiments and modifications are merely examples and are not intended to limit the scope of the invention. The above embodiments and modifications can be implemented in various other forms, and various omissions, substitutions, combinations, and changes can be made without departing from the spirit of the invention. Furthermore, each configuration, shape, and other specifications (structure, type, orientation, model, size, length, width, thickness, height, number, arrangement, position, material, etc.) can be modified as appropriate.

[0046] For example, the optical modulation element and the driving element are provided on the bottom surface of a recess in the base, but are not limited to this, and may be provided on a surface or back surface other than the bottom surface of the recess in the base. In other words, the base does not have to have a recess. However, when the optical modulation element or the driving element is housed in a recess in the base, it is possible to enhance protection by making it easier to avoid interference between the optical modulation element or the driving element and other components. Furthermore, the heat dissipation part is not limited to vias of ground wiring, but may be a layered conductor of ground wiring, a conductor of other wiring, or a heat dissipation part that is not wiring. [Explanation of Symbols]

[0047] 10, 10A…bass 11…Insulator 11a…Top surface 11b…Bottom surface 11c...side 11d…recess 11d1…Bottom surface (second surface) 11e…recess 11e1…Bottom surface (first surface) 11f…Step surface 12... Conductor 12D, 12D1, 12D2…(pair of) conductor wiring (differential wiring) 12I…Conductor wiring 12a...Strip-shaped conductor (wiring pattern) 12b... Via (heat dissipation section) 12c...Layered conductor 12c1, 12c2… patterns 12d...Bending part 12d1…bottom 12e, 211a, 231a, 232a...end 12G, 12G(12)... Ground wiring (heat dissipation section) 13…Bonding wire 14…Lid component 20…Optical Modulator 20a, 20b...surface 30…Driver element 30b1, 30b2… (a pair of) output terminals 40…Wiring components 41…Insulating layer 42... Conductor 100, 100A… Optical module 201...First Optical Modulation Section 202...Second Optical Modulation Section 211... Waveguide (First Waveguide) 212...Waveguide (second waveguide) 220...Main body 231, 232… (a pair of) electrodes 231b, 232b… terminals 234… Termination resistor X…direction (first direction) Y…direction (second direction) Z…direction (third direction) θ…Angle difference

Claims

1. An optical modulation element having an optical modulation section having a waveguide extending in a first direction, A driving element having a driving circuit for driving the aforementioned optical modulation section, A base on which the optical modulation element and the driving element are mounted has a first surface substantially aligned with the first direction and substantially aligned with a second direction intersecting the first direction, an insulator, and a conductor. Equipped with, The optical modulation element is provided on the first surface, The driving element is spaced apart from the optical modulation element in the second direction. An optical module in which heat dissipation sections are provided on the base in a portion aligned with the first direction and the second direction relative to the drive element in a third direction.

2. The optical modulation element comprises a first optical modulation section having a first waveguide as the waveguide, and a second optical modulation section having a second waveguide as the waveguide, which is spaced apart from the first waveguide in the second direction and substantially parallel to the first waveguide. The optical module according to claim 1, wherein the driving element comprises a driving element having a first driving circuit as the driving circuit for driving the first optical modulation unit and a second driving circuit as the driving circuit for driving the second optical modulation unit.

3. The optical module according to claim 2, wherein the heat dissipation section is the conductor that becomes ground potential.

4. The base has a second surface that faces in the opposite direction to the first surface and intersects with the first direction. The optical module according to claim 2 or 3, wherein the driving element is provided on the second surface.

5. The drive element has a pair of first output terminals that output differential electrical signals, The first optical modulation unit has a pair of first electrodes to which the differential electrical signal is input, The base has a pair of first differential wirings that, as conductors, pass through a position separated from the first surface in the opposite direction to the third direction, and electrically connect the pair of first output terminals and the pair of first electrodes, respectively. The optical module according to claim 4, wherein the first differential wiring is provided exposed on the second surface.

6. The drive element has a pair of first output terminals that output differential electrical signals, The first optical modulation unit has a pair of first electrodes to which the differential electrical signal is input, The base has a pair of first differential wirings that, as conductors, pass through a position separated from the first surface in the opposite direction to the third direction, and electrically connect the pair of first output terminals and the pair of first electrodes, respectively. The optical module according to claim 4, wherein the first differential wiring is provided on the second surface and covered with a coating layer made of a material with a lower dielectric constant than the base.

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