Optical module

Abstract

For example, the present invention provides an improved novel optical module having a configuration in which multiple optical modulation units and driving elements are not aligned in the longitudinal direction of the waveguide in the multiple optical modulation units. [Solution] The optical module comprises, for example, an optical modulation element having a first optical modulation section having a first waveguide extending in a first direction, and a second optical modulation section having a second waveguide that is spaced away from the first waveguide in a second direction intersecting the first direction and substantially parallel to the first waveguide, a driving element that is spaced away from the second waveguide in a second direction and drives the first optical modulation section and the second optical modulation section, and a base on which the optical modulation element and the driving element are mounted, wherein the optical modulation element is provided on a first surface, and the base has a pair of differential wirings that pass through a position spaced away from the first surface in the opposite direction to a third direction and electrically connect a pair of output terminals of the optical modulation element to a pair of electrodes of the first waveguide, respectively.

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 Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the configuration of Patent Document 1, since the plurality of optical modulation units and the driving element are arranged side by side in the longitudinal direction of the waveguide in the plurality of optical modulation units, the optical module becomes long in the longitudinal direction.

[0005] Therefore, one of the problems of the present invention is to provide, for example, an improved novel optical module having a configuration in which a plurality of optical modulation units and a driving element are not arranged side by side in the longitudinal direction of the waveguide in the plurality of optical modulation units.

Means for Solving the Problems

[0006] The optical module of the present invention comprises, for example, an optical modulation element having a first optical modulation section having a first waveguide extending in a first direction, and a second optical modulation section having a second waveguide that is spaced apart from the first waveguide in a second direction intersecting the first direction and substantially parallel to the first waveguide, a driving element that is spaced apart from the second waveguide in the second direction and drives the first optical modulation section and the second optical modulation section, a base having a first surface facing a third direction intersecting the first and second directions and intersecting the third direction, an insulator, and a conductor, on which the optical modulation element and the driving element are mounted, wherein the optical modulation element is provided on the first surface, the driving element has a pair of output terminals that output a differential electrical signal to be supplied to the first optical modulation section, the first optical modulation section has a pair of electrodes to which the differential electrical signal is input, and the base has a pair of differential wiring as the conductor that passes through a position spaced apart from the first surface in the opposite direction to the third direction and electrically connects the pair of output terminals and the pair of electrodes, respectively.

[0007] In the optical module, the base has a second surface that faces in the opposite direction to the first surface and intersects the third direction, and the driving element may be provided on the second surface.

[0008] In the optical module, the pair of differential wirings may be provided exposed on the second surface.

[0009] In the optical module, the pair of differential wirings may be provided covered on the second surface with a coating layer made of a material with a lower dielectric constant than the base.

[0010] The optical module of the present invention comprises, for example, an optical modulation element having a first optical modulation section having a first waveguide extending in a first direction, and a second optical modulation section having a second waveguide that is spaced apart from the first waveguide in a second direction intersecting the first direction and substantially parallel to the first waveguide, a driving element that is spaced apart from the second waveguide in the second direction and drives the first optical modulation section and the second optical modulation section, a base having a first surface facing a third direction intersecting the first and second directions and intersecting the third direction, a second surface facing the opposite direction from the first surface and intersecting the third direction, an insulator, and a conductor, on which the optical modulation element and the driving element are mounted, wherein the optical modulation element is provided on the first surface and the driving element is provided on the second surface.

[0011] In the optical module, the optical modulation element and the driving element may overlap at least partially in the third direction. [Effects of the Invention]

[0012] According to the present invention, for example, it is possible to provide an improved novel optical module having a configuration in which the multiple optical modulation units and driving elements are not aligned in the longitudinal direction of the waveguide in the multiple optical modulation units. [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 an optical module according to 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. [Figure 6] Figure 6 is an exemplary and schematic cross-sectional view of the optical module of the second embodiment at the same location as in Figure 5.

Mode for Carrying Out the Invention

[0014] Exemplary embodiments of the present invention are disclosed below. The configurations of the embodiments shown below, as well as the actions and results (effects) brought about by such configurations, are examples. The present invention can be realized by configurations other than those disclosed in the following embodiments. Further, according to the present invention, it is possible to obtain at least one of various effects (including derivative effects) obtained by the configuration.

[0015] The plurality of embodiments shown below have the same configuration. Therefore, according to the configuration of each embodiment, the same actions and effects based on such the same configuration can be obtained. Further, in the following, the same reference numerals are given to those same configurations, and redundant explanations may be omitted.

[0016] Also, in this specification, ordinal numbers can be given for convenience in order to distinguish parts, members, sites, directions, light, etc. Note that ordinal numbers do not indicate priorities or orders, nor do they specify numbers.

[0017] Also, 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 seen 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. Specifically, the insulator 11 is made of, for example, aluminum nitride. The conductor 12 is made of a material with high thermal conductivity and conductivity, such as a copper-based metal material. 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 the opposite direction of the Z direction. The lower surface 11b intersects the Z direction and faces the Z direction. Also, the side surfaces 11c each extend substantially along the Z direction and face the X direction or the Y direction.

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

[0043] As described above, in this embodiment, an optical module 100A (100) can be configured in which 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, and the optical module 100 can be easily applied in situations where there are length constraints in the X direction at the application location of the optical module 100.

[0044] [Second Embodiment] Figure 6 is a cross-sectional view of the optical module 100B(100) of the second embodiment at the same position as in Figure 5. The optical module 100B of this embodiment also has the same configuration as the optical module 100A of the first embodiment. Therefore, according to this embodiment, the same effects as the first embodiment can be obtained. However, in this embodiment, as shown in Figure 6, the optical modulation element 20 and the driving element 30 provided on the base 10B(10) overlap at least partially in the Z direction, which is different from the first embodiment. Such a configuration can be adopted when it is difficult for noise to be superimposed on the optical signal, or when the dielectric constant of the insulator 11 is relatively low and impedance reduction (mismatch) is unlikely to occur. According to this configuration, the amount of misalignment in the Y direction between the optical modulation element 20 and the driving element 30 can be reduced, so that the optical module 100 can be made longer in the X direction, and also longer in the Y direction.

[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; they may also be provided on surfaces other than the bottom surface of the recess in the base, or on the back surface. In other words, the base does not necessarily 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 easier to avoid interference between the optical modulation element or the driving element and other components, thus providing the advantage of increased protection. [Explanation of Symbols]

[0047] 10, 10A, 10B...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... Beer 12c...Layered conductor 12c1, 12c2… patterns 12d...Bending part 12d1…bottom 12e, 211a, 231a, 232a...end 12G, 12G(12)... Ground wiring 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, 100B… Optical Modules 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 comprising: a first optical modulation section having a first waveguide extending in a first direction; and a second optical modulation section having a second waveguide that is spaced apart from the first waveguide in a second direction intersecting the first direction and substantially parallel to the first waveguide; A driving element that is spaced apart from the second waveguide in the second direction and drives the first optical modulation section and the second optical modulation section, A base on which the optical modulation element and the driving element are mounted, having a first surface that faces a third direction intersecting the first direction and the second direction, an insulator, and a conductor, Equipped with, The optical modulation element is provided on the first surface, The drive element has a pair of output terminals that output differential electrical signals to be supplied to the first optical modulation unit. The first optical modulation unit has a pair of electrodes to which the differential electrical signal is input, The base has a pair of differential wirings as conductors, which electrically connect the pair of output terminals and the pair of electrodes, respectively, by passing through positions separated from the first surface in the opposite direction to the third direction.

2. The base has a second surface that faces in the opposite direction to the first surface and intersects with the third direction. The optical module according to claim 1, wherein the driving element is provided on the second surface.

3. The optical module according to claim 2, wherein the pair of differential wirings are provided exposed on the second surface.

4. The optical module according to claim 2, wherein the pair of differential wirings are provided on the second surface covered with a coating layer made of a material with a lower dielectric constant than the base.

5. An optical modulation element comprising: a first optical modulation section having a first waveguide extending in a first direction; and a second optical modulation section having a second waveguide that is spaced apart from the first waveguide in a second direction intersecting the first direction and substantially parallel to the first waveguide; A driving element that is spaced apart from the second waveguide in the second direction and drives the first optical modulation section and the second optical modulation section, A base on which the optical modulation element and the driving element are mounted, having a first surface facing a third direction intersecting the first and second directions, a second surface facing the opposite direction from the first surface and intersecting the third direction, an insulator, and a conductor, Equipped with, An optical module wherein the optical modulation element is provided on the first surface and the driving element is provided on the second surface.

6. The optical module according to claim 5, wherein the optical modulation element and the driving element overlap at least partially in the third direction.

Images