Optical semiconductor module

Abstract

This invention provides an optical semiconductor module. One embodiment of the optical semiconductor module includes: a substrate having transmission lines; a bulk material comprising a low-dielectric-constant material; an inductor mounted on the bulk material; a semiconductor laser element mounted on the substrate; and a housing housing the substrate, the semiconductor laser element, the bulk material, and the inductor. The inductor is connected to the transmission lines via a first lead. The semiconductor laser element is connected to the transmission lines via a second lead. The inductance of the first lead is greater than the inductance of the second lead.

Description

Technical Field

[0001] This disclosure relates to optical semiconductor modules.

[0002] This application claims priority based on Japanese Application No. 2020-186793, dated November 9, 2020, and invokes all the contents set forth in the aforementioned Japanese application. Background Technology

[0003] Japanese Patent Application Publication No. 2017-107920 discloses a semiconductor module having a laser section and an optical modulator section fabricated on a substrate. The semiconductor module includes a semiconductor laser integrating a DFB laser and an EA modulator, and a sub-plate with high-frequency wiring as coplanar wiring. The semiconductor laser has a ground electrode on its back side. A step consisting of upper and lower layers is formed on the upper surface of the sub-plate. The lower surface of the sub-plate is flat. The high-frequency wiring has a coplanar line formed on the upper surface of the sub-plate. The coplanar line includes ground wiring and signal wiring. A ground electrode is formed on the lower layer of the upper surface of the sub-plate. The semiconductor laser is configured such that the ground electrode on its back side is in contact with the ground electrode of the sub-plate. Summary of the Invention

[0004] One aspect of this disclosure includes a semiconductor module comprising: a substrate having transmission lines; a bulk material comprising a low-dielectric-constant material; an inductor mounted on the bulk material; a semiconductor laser element mounted on the substrate; and a housing housing the substrate, the semiconductor laser element, the bulk material, and the inductor. The inductor is connected to the transmission lines via a first lead. The semiconductor laser element is connected to the transmission lines via a second lead. The inductance of the first lead is greater than the inductance of the second lead.

[0005] Another aspect of the optical semiconductor module disclosed herein includes: a substrate; a bulk material made of a low dielectric constant and having transmission lines; an inductor mounted on the bulk material; a semiconductor laser element mounted on the substrate; and a housing housing the substrate, the semiconductor laser element, the bulk material, and the inductor. The inductor is connected to the transmission lines via a first lead. The semiconductor laser element is connected to the transmission lines via a second lead. The inductance of the first lead is greater than the inductance of the second lead. Attached Figure Description

[0006] Figure 1 This is a top view schematically illustrating the internal structure of the optical semiconductor module in an embodiment.

[0007] Figure 2 This is a schematic top view of a substrate carrying a semiconductor laser element and a block carrying an inductor in an optical semiconductor module.

[0008] Figure 3This is a schematic side view of an inductor mounted on a block.

[0009] Figure 4 It is a schematic representation of... Figure 2 Top view of the substrate with semiconductor laser element and the block with inductor in different optical semiconductor modules.

[0010] Figure 5 This is a diagram showing the equivalent circuit of an illustrated optical semiconductor module.

[0011] Figure 6 It means to Figure 5 The diagram of the equivalent circuit obtained by simplifying the equivalent circuit.

[0012] Figure 7 This is a diagram showing the equivalent circuit of the optical semiconductor module in the reference example.

[0013] Figure 8 This is a graph illustrating an example of the relationship between frequency and transmission characteristics.

[0014] Figure 9 This is a graph illustrating an example of the relationship between frequency and transmission characteristics.

[0015] Figure 10 This is a diagram showing the equivalent circuit of a modified optical semiconductor module.

[0016] Figure 11 It is a schematic representation Figure 2 Side view of temperature control components, substrate, and semiconductor laser element of an optical semiconductor module. Detailed Implementation

[0017] Specific examples of optical semiconductor modules according to embodiments of the present disclosure will be described with reference to the accompanying drawings. The invention is not limited to these examples, but is defined by the scope of the claims and is intended to include all modifications within the scope equivalent to the claims. In the description of the drawings, the same or equivalent elements are labeled with the same reference numerals, and repeated descriptions are omitted where appropriate. For ease of understanding, some parts of the drawings are depicted in a simplified or exaggerated manner, and the dimensions, proportions, etc., are not limited to what is shown in the drawings.

[0018] (First Implementation)

[0019] Figure 1This is a top view schematically showing the internal structure of the optical semiconductor module 1 according to the first embodiment. The optical semiconductor module 1 includes, for example, a rectangular housing 2 and an external terminal 3 located at one end of the housing 2 along its length direction (direction D1). The external terminals 3 are arranged along the width direction (direction D2) of the housing 2 at one end along direction D1. Direction D2 is a direction intersecting direction D1. The external terminals 3 include, for example, terminals for receiving high-speed electrical signals from the outside, terminals for receiving drive current from a laser diode, terminals for receiving drive current from a TEC (thermal energy source), monitoring terminals for detecting the temperature of the laser diode, and terminals for providing a ground potential (reference potential). Signals exchanged with the outside via the external terminals 3 include high-speed signals and low-speed signals. Low-speed signals include DC signals. The housing 2 has an inner wall 2b that divides the internal space S of the housing 2. At the end of the housing 2 along direction D1, opposite to the external terminals 3, a light output section 4 for outputting light L (light transmission signal) is provided.

[0020] The optoelectronic semiconductor module 1 has, for example, a transmission line 5, a pad 6 as a DC pad, and a TEC (Thermo Electric Cooler) 7 as a temperature control element in the internal space S of the housing 2. Figure 2 This is a schematic top view of the enlarged upper structure of the TEC7. Figure 11 This is a schematic side view representing the upper structure of the TEC7. (Example) Figure 1 and Figure 2 As shown, the optical semiconductor module 1 includes a TEC7, an AlN (Aluminum Nitride) substrate 8 (substrate) on which a semiconductor laser element 10 is mounted, and a block 9 on which an inductor 15 is mounted. Transmission lines 5 and pads 6 are formed on the inner surface of the housing 2. The transmission lines 5 and pads 6 are connected to external terminals 3 via wiring that penetrates the inner wall 2b. The wiring connecting each of the transmission lines 5 and pads 6 to the external terminals 3 is formed, for example, by metal plating or vapor deposition. The transmission line 5 includes a signal line 5s extending in one direction at a distance from a parallel grounding line 5g.

[0021] For example, the AlN substrate 8 is mounted on the TEC7 in direction D3, which is the height direction. Direction D3 is the direction that intersects with directions D1 and D2. The housing 2 houses, for example, the TEC7, the AlN substrate 8, the block 9, the semiconductor laser element 10, and the inductor 15 within the internal space S. The TEC7 has a heat dissipation surface 7a and a temperature control surface 7b. The TEC7 is mounted on the housing 2 such that the heat dissipation surface 7a contacts the housing 2. The temperature control surface 7b is located in the opposite position to the heat dissipation surface 7a in direction D3. For example, the heat dissipation surface 7a and the temperature control surface 7b are planes parallel to directions D1 and D2. More specifically, the AlN substrate 8 is mounted on the temperature control surface 7b, for example, in contact with it. The AlN substrate 8 has a first surface 8a as its lower surface and a second surface 8b as its upper surface. The first surface 8a is in surface contact with the temperature control surface 7b. The second surface 8b is the opposite side of the first surface 8a. The AlN substrate 8 has a second surface 8b on the side opposite to the TEC7. A semiconductor laser element 10 is mounted on the second surface 8b. A block 9 is arranged side-by-side with the AlN substrate 8 on the TEC7. The TEC7, for example, controls the temperature of the semiconductor laser element 10. For example, if a predetermined current flows through the TEC7, heat is absorbed on the temperature control surface 7b, and the absorbed heat is dissipated on the heat dissipation surface 7a. At this time, the semiconductor laser element 10 is cooled via the AlN substrate 8. For example, if a current flows through the TEC7 in the opposite direction to the predetermined current, heat is absorbed on the heat dissipation surface 7a, and the absorbed heat is dissipated on the temperature control surface 7b. At this time, the semiconductor laser element 10 is heated via the AlN substrate 8. The block 9 is made of a low-dielectric-constant material. For example, the block 9 is formed of quartz. For example, the relative permittivity of the low-dielectric-constant material is 3 to 5. The AlN substrate 8, for example, includes an insulator. The relative permittivity of the low-dielectric-constant material of the block 9 is smaller than the relative permittivity of the insulator of the AlN substrate 8. For example, the relative permittivity of the insulator is 8 to 10. The semiconductor laser element 10 is, for example, an electric-absorption modulator integrated laser (EML). For instance, the semiconductor laser element 10 includes a laser diode 10b and an optical modulator 10c (modulator). By maintaining the temperature of the semiconductor laser element 10 at a predetermined temperature, the optical and electrical characteristics of the semiconductor laser element 10 can be stabilized relative to changes in the external ambient temperature. For example, the peak wavelength of the optical signal output from the semiconductor laser element 10 can be maintained within a predetermined range.

[0022] Figure 3 This is a schematic side view showing block 9 and inductor 15. (Example) Figure 2 and Figure 3As shown, the block 9 has a third surface 9a as its lower surface and a fourth surface 9b as its upper surface. The third surface 9a is connected to the temperature control surface 7b. The fourth surface 9b is the opposite surface to the third surface 9a. The fourth surface 9b is opposite to the inductor 15. A wiring 9c is formed on the fourth surface 9b. The block 9 is, for example, placed on the temperature control surface 7b of the TEC7. The third surface 9a of the block 9 is, for example, in contact with the temperature control surface 7b of the TEC7. The TEC7 is placed on the inner surface of the housing 2 in such a way that its heat dissipation surface 7a contacts the inner surface of the housing 2. The fourth surface 9b is, for example, a plane parallel to directions D1 and D2. The wiring 9c includes, for example, a first wiring 9d disposed on the side of the external terminal 3 and a second wiring 9f disposed on the side of the light output section 4. For example, in direction D1, the first wiring 9d is disposed between the external terminals (multiple) and the second wiring 9f. For example, in direction D1, the second wiring 9f is disposed between the first wiring 9d and the light output section 4. The first wiring 9d and the second wiring 9f are insulated from each other. A resistor 16 is mounted on the second surface 9b. The resistor 16 is disposed, for example, between the first wiring 9d and the second wiring 9f. The resistor 16 is electrically connected between the first wiring 9d and the second wiring 9f. An inductor 15 is electrically connected between the first wiring 9d and the second wiring 9f. One end (first electrode) of the inductor 15 is connected to the first wiring 9d, and the other end (second electrode) of the inductor 15 is connected to the second wiring 9f. The resistor 16 is connected in parallel with the inductor 15 between the first wiring 9d and the second wiring 9f. The opto-semiconductor module 1 includes an RC series circuit 17. The inductor 15 is electrically connected between the RC series circuit 17 and the transmission line 11, which will be described later. The inductor 15 functions, for example, as a bias device T. The bias device T supplies a bias (DC potential) to the transmission line 11. The bias becomes the reference potential for the high-frequency signal propagating on the transmission line 11. The bias resistor T has high impedance at high frequencies when viewed from transmission line 11, thus minimizing its impact on high-frequency signals. Inductor 15 is mounted on first wiring 9d and second wiring 9f. For example, one electrode (first electrode) of inductor 15 is bonded to first wiring 9d via solder, and the other electrode (second electrode) of inductor 15 is bonded to second wiring 9f via solder. An RC series circuit can also be constructed, for example, by forming pads 6 for mounting resistors and pads 6 for mounting capacitors on the inner surface of housing 2, and connecting these pads with wiring. The wiring connecting these pads can also be formed by plating or vapor deposition.

[0023] The AlN substrate 8 has a transmission line 11 on its second surface 8b opposite to the TEC7. The transmission line 11 includes a high-frequency wiring 11b extending in one direction (D1 direction) while maintaining a certain distance from a parallel ground wiring 11c. For example, the ground wiring 11c includes a first ground wiring portion 11d housing a die 12, a chip 13, and a resistor 14, and a second ground wiring portion 11f located opposite to the first ground wiring portion 11d when viewed from the high-frequency wiring 11b. The second ground wiring portion 11f is located opposite to the first ground wiring portion 11d when viewed from the high-frequency wiring 11b. In other words, the high-frequency wiring 11b is disposed between the first ground wiring portion 11d and the second ground wiring portion 11f in direction D2. Furthermore, the first ground wiring portion 11d and the second ground wiring portion 11f are interconnected between the high-frequency wiring 11b and the light output unit 4. The grounding wiring 11c may not be a wiring that extends in one direction like the transmission line 11, or it may be a wiring pattern with a wide section that maintains a certain distance from the transmission line.

[0024] Leads W1, W2, W3, and W4 extend from the die 12, the first ground wiring portion 11d, the high-frequency wiring portion 11b, and the second ground wiring portion 11f, respectively. For example, the optical semiconductor module 1 also includes a lead W5 connecting the die 12 and the laser diode 10b, a lead W6 connecting one end of the resistor 14 and the modulator 10c, and a lead W7 connecting the high-frequency wiring portion 11b and the modulator 10c.

[0025] Furthermore, the opto-semiconductor module 1 includes leads W8 connecting the RC series circuit 17 and the inductor 15, and leads W9 connecting the inductor 15 and the transmission line 11. Leads W1, W2, W3, W4, W5, W6, W7, W8, and W9 are, for example, bond wires. The diameters of leads W1, W2, W3, W4, W5, W6, W7, W8, and W9 are, for example, 18 μm, 25 μm, or 50 μm. The diameters of each lead W1, W2, W3, W4, W5, W6, W7, W8, and W9 can be the same or different. Additionally, leads W1, W2, W3, W4, W5, W6, W7, W8, and W9 may not be bond wires, but may be striplines. Striplines, for example, do not have a circular cross-section like bond wires, but have a flat cross-section. For example, in a stripline, the transverse width of the cross-section is more than twice the thickness of the cross-section. Lead W9 corresponds to the first lead connecting inductor 15 and transmission line 11. Lead W7 corresponds to the second lead connecting semiconductor laser element 10 and transmission line 11. The inductance of lead W9 is greater than that of lead W7. For example, lead W9 can be longer than lead W7. The cross-sectional area of ​​lead W9 (as an example, the diameter) can be smaller than that of lead W7.

[0026] (Second Implementation)

[0027] Next, refer to Figure 4 The optical semiconductor module 21 of the second embodiment will be described. A portion of the structure of the optical semiconductor module 21 of the second embodiment is identical to a portion of the structure of the optical semiconductor module 1 described above. Therefore, for descriptions identical to those of the optical semiconductor module 1, the same reference numerals as those of the optical semiconductor module 1 are used, and descriptions are appropriately omitted. For example... Figure 4 As shown, in the optical semiconductor module 21, the block 9 has a transmission line 22 on its fourth surface 9b. The transmission line 22 includes a high-frequency wiring 22b that extends in one direction at a distance from the parallel ground wiring 22c. The ground wiring 22c includes, for example, a third ground wiring portion 22d and a fourth ground wiring portion 22f located on the opposite side of the third ground wiring portion 22d when viewed from the high-frequency wiring 22b. For example, in the optical semiconductor module 21, the AlN substrate 8 only has a first ground wiring portion 11d.

[0028] The optical semiconductor module 21 also includes, for example, a lead W10 that connects the third ground wiring portion 22d formed on the block 9 and the first ground wiring portion 11d formed on the AlN substrate 8. In the optical semiconductor module 21, a lead W9 extending from the inductor 15 is connected to the transmission line 22. A lead W7 connects the high-frequency wiring 22b and the modulator 10c. Similar to the optical semiconductor module 1 described above, the inductance of the lead W9 is greater than that of the lead W7.

[0029] Next, the effects obtained from the optical semiconductor modules 1 and 21 of the above embodiments will be explained. In the optical semiconductor module 1 of the first embodiment, as shown... Figure 2 As illustrated, the AlN substrate 8 has a transmission line 11. An inductor 15 is mounted on a block 9. A semiconductor laser element 10 is mounted on the AlN substrate 8. The block 9 is made of a low dielectric constant material. Therefore, the parasitic capacitance of the wiring 9c formed on the fourth surface 9b relative to the ground potential can be reduced. The inductance of the lead W9 connecting the inductor 15 and the transmission line 11 is greater than the inductance of the lead W7 connecting the semiconductor laser element 10 and the transmission line 11. By making the inductance of the lead W9 connecting the inductor 15 and the transmission line 11 greater, the influence on high-frequency signals propagating on the high-frequency wiring 11b can be suppressed even with the inductor 15 present. Moreover, a wide bandwidth of the frequency characteristics of the optical semiconductor module 1 can be achieved.

[0030] In the optical semiconductor module 21 of the second embodiment, such as Figure 4As illustrated, block 9 has transmission line 22, and inductor 15 is mounted on block 9. Semiconductor laser element 10 is mounted on AlN substrate 8. In opto-semiconductor module 21, similar to opto-semiconductor module 1, block 9 is made of a low dielectric constant material, thus reducing the parasitic capacitance of wiring 9c formed on the second surface 9b. Compared to the first embodiment, transmission line 22 is formed on a low dielectric constant material, thus suppressing transmission losses (e.g., dielectric tangent) when transmitting high-frequency signals. In addition, similar to wiring 9c, the parasitic capacitance of transmission line 22 can be reduced. Therefore, the frequency characteristics of transmission line 22 can be further widened. The inductance of lead W9 connecting inductor 15 and transmission line 22 is greater than the inductance of lead W7 connecting semiconductor laser element 10 and transmission line 22. Therefore, even with inductor 15 present, the influence on high-frequency signals propagating on high-frequency wiring 22b can be suppressed. Moreover, it can achieve wideband capabilities for the optical semiconductor module 21.

[0031] Figure 5 This is a diagram showing the equivalent circuit associated with the biaser T of the optical semiconductor module 1 (or optical semiconductor module 21). The biaser T includes, for example, lead W9, inductor 15, resistor 16, and RC series circuit 17. Figure 6 It is Figure 5 The equivalent circuit is obtained by simplifying the equivalent circuit. For example... Figure 5 and Figure 6 As shown, the inductance of lead W9 is set to L, and the resistance of resistor 16 is set to R. para Set the resistance of RC series circuit 17 to R. dump And, when R = R para +R dump When the inductor L and the series circuit of the RC parallel circuit are connected, the resonant frequency ω0 is as shown in equation (1).

[0032] [Formula 1]

[0033]

[0034] In equation (1), when R→∞, ω0 is equal to the resonant frequency in the series LC resonant circuit of inductor L and capacitor C. On the other hand, the impedance Z (ω=ω0) at the resonant frequency ω0 is as shown in equation (2).

[0035] [Formula 2]

[0036]

[0037] In the optical semiconductor module 1 (or optical semiconductor module 21), since R is not 0, the impedance Z (ω = ω0) is not 0, and the smaller ω0 is (the larger L is), the higher the impedance Z becomes. Therefore, under the condition that the product CR of capacitance C and resistance R in equations (1) and (2) is constant, the larger the value of L is, the more effectively the impedance reduction at the resonant frequency can be suppressed. As described above, when the inductance L of the lead W9 extending from the inductor 15 is large, the frequency characteristics of the transmission line 11 can be widened under the condition of having the inductor 15.

[0038] In this embodiment, the block 9 also has a resistor 16 connected in parallel with the inductor 15. Therefore, the damping effect of the resistor 16 can reduce the tilt associated with parasitic capacitance.

[0039] In this embodiment, the optical semiconductor module 1 (or optical semiconductor module 21) also includes an RC series circuit 17. An inductor 15 is electrically connected between the RC series circuit 17 and the transmission line 11 (or transmission line 22). In this case, transmission tilt can be further reduced.

[0040] In this embodiment, the block 9 is disposed adjacent to the AlN substrate 8 on the temperature control surface 7b of the TEC7. Therefore, the block 9, on which the inductor 15 is mounted, can be disposed adjacent to the AlN substrate 8. For example, when viewed from direction D3, the distance between the block 9 and the AlN substrate 8 can be reduced to 50–150 μm. This allows the inductor 15 to be disposed close to the transmission line 11 formed on the AlN substrate 8. Alternatively, the transmission line 22 can be formed on the fourth surface 9b of the block 9. In this case, the inductor 15 can be disposed close to the transmission line 22. Furthermore, the AlN substrate 8 and the block 9 are, for example, mounted on the temperature control surface 7b of the TEC7. However, if the semiconductor laser element 10 does not require temperature control, the AlN substrate 8 and the block 9 can also be directly mounted on the inner surface of the housing 2.

[0041] In this embodiment, the dielectric constant of the low-dielectric-constant material of the bulk 9 is smaller than the dielectric constant of the insulator of the AlN substrate 8. Therefore, by making the dielectric constant of the low-dielectric-constant material of the bulk 9 smaller than the dielectric constant of the insulator of the AlN substrate 8, parasitic capacitance can be further reduced. At this time, the thickness of the AlN substrate 8 can be made approximately the same as the thickness of the bulk 9. As a result, compared with the case where the inductor 15 is mounted on the AlN substrate 8, the parasitic capacitance of the wiring connected to the inductor 15 can be reliably reduced.

[0042] In this embodiment, the inductance of lead W9 can be more than twice that of lead W7. In this case, further widening of the bandwidth can be achieved.

[0043] Next, embodiments will be described. The present invention is not limited to the following embodiments. The optical semiconductor module involved in the embodiments is the optical semiconductor module 1 described above. For example... Figure 5 As shown, the optical semiconductor module involved in the embodiment includes a resistor 16 and an RC series circuit 17 configured in parallel with the inductor 15. Figure 7 This represents the equivalent circuit related to the biaser T of the optical semiconductor module involved in the reference example. For example... Figure 7 As shown, the optical semiconductor module involved in the reference example does not have a structure equivalent to resistor 16 and RC series circuit 17.

[0044] Figure 8 The results of simulations of the frequency characteristics (transmission characteristics) of the transmission line 11 in the optical semiconductor module of each of the above embodiments and reference examples are shown. Figure 8 In this diagram, the horizontal axis represents the frequency of the signal transmitted through the transmission line, and the vertical axis, expressed in decibels (dB), represents the ratio of the signal strength of the signal output from the transmission line (output signal strength) to the signal strength of the signal input to the transmission line (input signal strength). For example, 0dB represents the output signal strength when it equals the input signal strength. A transmission characteristic value greater than 0dB indicates that the output signal strength is greater than the input signal strength, and a transmission characteristic value less than 0dB indicates that the output signal strength is less than the input signal strength. That is, when there are losses in the transmission line, the output signal strength is smaller than the input signal strength, and therefore the transmission characteristic value decreases. Figure 8 As shown, in the optical semiconductor module of the reference example without resistor 16 and RC series circuit 17, a large resonance tilt (transmission tilt) occurs near a frequency of 30 GHz. Resonance tilt indicates a significant loss of signal strength as the signal propagates through transmission line 11. In contrast, in the optical semiconductor module of the embodiment, similar to the case without bias T, almost no resonance tilt occurs. That is, the loss is significantly suppressed. Bias T is required to provide a reference potential for the high-frequency signal propagating on the transmission line. The fact that the equivalent characteristics are not degraded when bias T is present compared to the case without bias T is an example demonstrating the usefulness of the embodiment compared to the reference example.

[0045] Figure 9 This represents the result of a simulation of the transmission characteristics in the optical semiconductor module described in the embodiment, with the inductance of lead W9 changed. For example... Figure 9 As shown, with an inductance of 300 pH for lead W9, some skew and high-frequency losses occur. In contrast, with an inductance of 600 pH or higher (600 pH or 1.2 nH), it can be seen that, similar to the case without bias T, almost no skew and high-frequency losses occur.

[0046] The embodiments and examples of the optical semiconductor module disclosed herein have been described above. However, the present invention is not limited to the above-described embodiments or examples. Those skilled in the art will readily recognize that the present invention can be modified and altered in various ways within the scope of the spirit described in the claims.

[0047] For example, in the above-described embodiments, such as Figure 5 As illustrated, optical semiconductor module 1 and optical semiconductor module 21, which include resistor 16 and RC series circuit 17, have been described. However, for example, Figure 10 As shown, it can also be a photonic semiconductor module without the RC series circuit 17. At least one of the resistor 16 and the RC series circuit 17 can also be omitted.

[0048] In the above embodiments, an example of mounting the die 12, chip 13, and resistor 14 on the transmission line 11 has been described. However, the types and quantities of components mounted on the transmission line 11 are not limited to the above examples and can be appropriately varied. In the above embodiments, an example of an EML semiconductor laser element 10 has been described. However, the semiconductor laser element may also be a semiconductor laser element other than an EML.

[0049] In the above embodiments, an example of an AlN substrate 8 and a quartz substrate 9 has been described. However, the substrate material can also be other than AlN. The bulk material can also be made of alumina, FPC, or polyimide. That is, as long as the dielectric constant of the low-dielectric-constant material of the bulk material 9 is smaller than the dielectric constant of the insulator of the substrate, the materials of the substrate and the bulk material are not particularly limited.

Claims

1. An optical semiconductor module, wherein, have: The substrate has transmission lines; The bulk material is composed of a low dielectric constant material, wherein the dielectric constant of the low dielectric constant material is smaller than the dielectric constant of the insulator of the substrate; An inductor is mounted on the block. A semiconductor laser element is mounted on the substrate; and The housing houses the substrate, the semiconductor laser element, the bulk material, and the inductor. The transmission line includes a high-frequency wiring that extends along a first direction while maintaining a certain distance from the parallel grounding wiring. The inductor is connected to the high-frequency wiring via a first lead. The semiconductor laser element is connected to the high-frequency wiring via a second lead. The inductance of the first lead is greater than the inductance of the second lead.

2. The optical semiconductor module according to claim 1, wherein, The block also has a resistor connected in parallel with the inductor.

3. The optical semiconductor module according to claim 1, wherein, The optical semiconductor module also has an RC series circuit. The inductor is connected between the RC series circuit and the transmission line.

4. The optical semiconductor module according to claim 1, wherein, The block is disposed adjacent to the substrate inside the housing.

5. The optical semiconductor module according to claim 1, wherein, The inductance of the first lead is more than twice the inductance of the second lead.

6. An optical semiconductor module, wherein, have: substrate; The bulk material is made of a low dielectric constant material and has transmission lines, wherein the dielectric constant of the low dielectric constant material is smaller than the dielectric constant of the insulator of the substrate; An inductor is mounted on the block. A semiconductor laser element is mounted on the substrate; and The housing houses the substrate, the semiconductor laser element, the bulk material, and the inductor. The transmission line includes a high-frequency wiring that extends along a first direction while maintaining a certain distance from the parallel grounding wiring. The inductor is connected to the high-frequency wiring via a first lead. The semiconductor laser element is connected to the high-frequency wiring via a second lead. The inductance of the first lead is greater than the inductance of the second lead.

7. The optical semiconductor module according to claim 6, wherein, The block also has a resistor connected in parallel with the inductor.

8. The optical semiconductor module according to claim 6, wherein, The optical semiconductor module also has an RC series circuit. The inductor is connected between the RC series circuit and the transmission line.

9. The optical semiconductor module according to claim 6, wherein, The block is disposed adjacent to the substrate inside the housing.

10. The optical semiconductor module according to claim 6, wherein, The inductance of the first lead is more than twice the inductance of the second lead.

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