Semiconductor laser source device

Abstract

Pins 1 to 3 (2b to 2e) pass through the metal socket (1). A support block (4) is disposed on the metal socket (1). A temperature control module (5) is mounted on the side of the support block (4) and has a lower substrate (5b), an upper substrate (5c), and multiple thermoelectric elements (5a) sandwiched between the upper substrate (5c) and the lower substrate (5b). The back side of the dielectric substrate (6) is joined to the upper substrate (5c) of the temperature control module (5). Two differential drive signal lines (7a, 7b) are disposed on the main surface of the dielectric substrate (6). A semiconductor optical modulation element (10) and a temperature sensor (11) are mounted on the main surface of the dielectric substrate (6). A first conductive wire (14b, 14c) connects one end of the differential drive signal lines (7a, 7b) to the semiconductor optical modulation element (10). The second conductive wire (14d, 14e) connects the other end of the differential drive signal line (7a, 7b) to pin 1 (2b, 2c). The third conductive wire (14f, 14g) connects the temperature sensor (11) to pin 2 (2d). The fourth conductive wire (14j, 14k) connects the temperature control module (5) to pin 3 (2e).

Description

Technical Field

[0001] This disclosure relates to a semiconductor laser source device that uses a temperature control module to control the temperature of a semiconductor optical modulation element. Background Technology

[0002] The widespread adoption of social networking services (SNS), video sharing services, and other similar services is developing on a global scale, accelerating the increase in data transmission capacity. To cope with the high-speed, high-capacity transmission of signals within limited installation space, optical transceivers are being developed for high speed and miniaturization. For optical equipment, in addition to the requirements of high speed and low cost, low power consumption is also required to control operating costs.

[0003] As a laser source device equipped with a semiconductor optical modulation element, the TO-CAN (Transistor-Outlined CAN) type, which can be inexpensively commercialized, is generally used. In the TO-CAN construction, glass is typically used to seal and fix the pins to the metal socket. Due to the pressure generated by the difference in their respective coefficients of thermal expansion, the pin configuration and the spacing between the pins become important to ensure high hermeticity.

[0004] Semiconductor optical modulation elements experience changes in oscillation wavelength or light output due to heat generation. Therefore, for laser source devices equipped with semiconductor optical modulation elements, a temperature control module is used to maintain the temperature of the semiconductor optical modulation element at a constant level (for example, see Patent Document 1).

[0005] Patent Document 1: Japanese Patent Application No. 2011-518381

[0006] In conventional designs, conductive wires are used to connect the high-frequency circuitry of a first dielectric substrate on which a semiconductor optical modulator is mounted, and the high-frequency circuitry of a second dielectric substrate connected to pins. The presence of the second dielectric substrate increases cost and reduces the mounting flexibility of the first dielectric substrate. Furthermore, the increased distance from the pins to the semiconductor optical modulator leads to deterioration of high-frequency characteristics due to impedance mismatch or increased inductance. Additionally, the long distance from the temperature control module to the semiconductor optical modulator results in poor heat dissipation and increased power consumption. Moreover, the single-layer driving method for inputting electrical signals to the semiconductor optical modulator further increases power consumption. Summary of the Invention

[0007] This disclosure is made to solve the aforementioned problems, and its purpose is to provide a semiconductor laser source device that can reduce costs and power consumption, and improve the mounting freedom of the dielectric substrate and high-frequency characteristics.

[0008] The semiconductor laser source device disclosed herein is characterized by comprising: a metal socket; pins 1 to 3 extending through the metal socket; a support block disposed on the metal socket; a temperature control module mounted on the side of the support block, having a lower substrate, an upper substrate, and a plurality of thermoelectric elements sandwiched between the upper and lower substrates; a dielectric substrate with its back side bonded to the upper substrate of the temperature control module; a differential drive signal line disposed on the main surface of the dielectric substrate; a semiconductor optical modulation element mounted on the main surface of the dielectric substrate; a temperature sensor mounted on the main surface of the dielectric substrate; a first conductive wire connecting one end of the differential drive signal line to the semiconductor optical modulation element; a second conductive wire connecting the other end of the differential drive signal line to the first pin; a third conductive wire connecting the temperature sensor to the second pin; and a fourth conductive wire connecting the temperature control module to the third pin.

[0009] In this disclosure, a temperature control module is mounted on the side of a support block, which is positioned on a metal tube socket. A dielectric substrate with a semiconductor optical modulation element mounted on it is bonded to the temperature control module. This eliminates the need for a second dielectric substrate, thus reducing costs. Furthermore, the increased size of the dielectric substrate enhances its mounting flexibility. Additionally, the ability to connect signal lines and pins on the main surface of the dielectric substrate using short conductive wires improves high-frequency characteristics. Moreover, the shorter distance from the temperature control module to the semiconductor optical modulation element improves heat dissipation and absorption, reducing power consumption. Finally, the differential drive method for inputting electrical signals to the semiconductor optical modulation element reduces the voltage amplitude of the signal generator compared to conventional single-layer drive methods, thereby reducing the power consumption of the signal generator. Attached Figure Description

[0010] Figure 1 This is a front perspective view of the semiconductor laser source device according to Embodiment 1.

[0011] Figure 2 This is a top view of the semiconductor laser source device according to Embodiment 1.

[0012] Figure 3 This is a side view of the semiconductor laser source device according to Embodiment 1.

[0013] Figure 4 This is a perspective view of the back of the semiconductor laser source device according to Embodiment 1.

[0014] Figure 5This is a graph comparing the power consumption of the temperature control module in the conventional configuration and the configuration of this embodiment.

[0015] Figure 6 This is a front perspective view of the semiconductor laser source device according to Embodiment 2.

[0016] Figure 7 This is a front perspective view of the semiconductor laser source device according to Embodiment 3.

[0017] Figure 8 This is a schematic diagram of the semiconductor laser source device according to Embodiment 4. Detailed Implementation

[0018] The semiconductor laser source apparatus according to the embodiments will be described with reference to the accompanying drawings. The same or corresponding components are labeled with the same reference numerals, and repeated descriptions are sometimes omitted.

[0019] Implementation Method 1

[0020] Figure 1 This is a front perspective view of the semiconductor laser source device according to Embodiment 1. Figure 2 This is a top view of the semiconductor laser source device according to Embodiment 1. Figure 3 This is a side view of the semiconductor laser source device according to Embodiment 1. Figure 4 This is a perspective view of the back of the semiconductor laser source device according to Embodiment 1.

[0021] The metal socket 1 is a generally circular plate, for example, a metal socket substrate made by applying Au plating to the surface of a material with high thermal conductivity such as Cu. Multiple pins 2a to 2f pass through the metal socket 1. Glass 3 is generally used to fix the pins 2a to 2f to the metal socket 1. When impedance mismatch occurs, multiple reflections of the signal deteriorate the frequency response characteristics, making high-speed modulation difficult. Therefore, the glass 3 is made of a material with a low dielectric constant to achieve the same impedance as the signal generator.

[0022] Support block 4 is disposed on metal tube seat 1. Support block 4 is a block of metal material formed by, for example, applying Au plating to the surface of a material with high thermal conductivity such as Cu. Support block 4 can be installed on metal tube seat 1 as a separate component from metal tube seat 1, or metal tube seat 1 and support block 4 can be integrally formed.

[0023] The temperature control module 5 is mounted on the side of the support block 4. The temperature control module 5 consists of a lower substrate 5b and an upper substrate 5c made of materials such as AlN, sandwiching multiple thermoelectric elements 5a made of materials such as BiTe. The side of the support block 4 is bonded to the lower substrate 5b of the temperature control module 5 using a bonding material such as SnAgCu solder or AuSn solder. The lower substrate 5b has a protrusion that extends upwards from the upper substrate 5c, and a metallized portion 5d for supplying power to the thermoelectric elements 5a is provided on this protrusion.

[0024] The dielectric substrate 6 is formed into a square plate shape, and is made of ceramic materials such as aluminum nitride (AlN), providing electrical insulation and heat transfer functions. The dielectric substrate 6 has a main surface, a back surface, and four side surfaces that are opposite to each other. The lower side surface of the dielectric substrate 6 faces the upper surface of the metal tube seat 1, and the upper side surface is the opposite side of the lower side surface. The back surface of the dielectric substrate 6 is bonded to the upper substrate 5c of the temperature control module 5. Two differential drive signal lines 7a and 7b, a ground conductor 8, and a temperature control module conductor 9 are disposed on the main surface of the dielectric substrate 6 by Au plating and metallization. The differential drive signal lines 7a and 7b are microstrip lines or coplanar lines, having an impedance equal to the output impedance of the signal generator. The temperature control module conductor 9 extends from the main surface of the dielectric substrate 6 to the upper side surface.

[0025] The semiconductor optical modulation element 10, temperature sensor 11, and ceramic block 12 are mounted on the main surface of the dielectric substrate 6. For example, SnAgCu solder or AuSn solder are used as bonding materials for bonding the temperature sensor 11 and ceramic block 12 to the dielectric substrate 6. The modulator section of the semiconductor optical modulation element 10 is composed of multiple electric field absorption type optical modulators. The temperature sensor 11 is, for example, a thermistor. The ceramic block 12 is, for example, an AlN substrate, and a conductive film is provided on its upper surface. The light-receiving element 13 is mounted on the metal tube seat 1 or a secondary abutment. Here, the light-receiving element 13 is positioned on the negative Z-axis side of the semiconductor optical modulation element 10.

[0026] Conductive wire 14a connects the distributed feedback laser diode of the semiconductor optical modulation element 10 to pin 2a. Conductive wires 14b and 14c connect one end of the two differential drive signal lines 7a and 7b to the EAM (electro-absorption modulator) electrode of the semiconductor optical modulation element 10, respectively. Conductive wires 14d and 14e connect the other end of the two differential drive signal lines 7a and 7b to pins 2b and 2c, respectively. Conductive wire 14f connects the temperature sensor 11 to the conductive film of the ceramic block 12. Conductive wire 14g connects the conductive film of the ceramic block 12 to pin 2d. Conductive wires 14h and 14i connect the ground conductor 8 to the metal socket 1. Conductive wire 14j connects the temperature control module conductor 9 disposed on the main surface of the dielectric substrate 6 to the metallized portion 5d of the temperature control module 5. Conductive wire 14k connects the temperature control module conductor 9 disposed on the upper side of the dielectric substrate 6 to pin 2e. The conductive wire 14l connects the light-receiving element 13 and the pin 2f.

[0027] The semiconductor optical modulation element 10 is, for example, a modulator-integrated laser diode (EAM-LD) monolithically integrating an electric field absorption type optical modulator using an InGaAsP-based quantum well absorption layer and a distributed feedback laser diode. Laser light is emitted from the light-emitting point of the semiconductor optical modulation element 10 along an optical axis perpendicular to the chip's end face and parallel to the chip's main surface. Power can be supplied to the distributed feedback laser diode either directly via a conductive wire 14a from pin 2a, or, depending on the manufacturing method, via a conductor disposed on the dielectric substrate 6 as a relay.

[0028] The differential electrical signals input to pins 2b and 2c are transmitted to the differential drive signal lines 7a and 7b via conductive wires 14d and 14e, and then applied to the modulator of the semiconductor optical modulation element 10 via conductive wires 14b and 14c. Here, the electrical signals input to pins 2b and 2c are electromagnetically coupled to the metal socket 1. The grounding conductor 8 of the dielectric substrate 6, which is connected to the metal socket 1, the support block 4, and the temperature control module 5, functions as AC ground.

[0029] Since the oscillation wavelength changes when the temperature of the semiconductor optical modulator 10 changes, it is necessary to keep the temperature constant. Therefore, when the temperature of the semiconductor optical modulator 10 rises, the temperature control module 5 cools it; conversely, when the temperature decreases, the temperature control module 5 heats up, thus keeping the temperature of the semiconductor optical modulator 10 constant. The heat generated in the semiconductor optical modulator 10 is transferred to the upper substrate 5c of the temperature control module 5 via the dielectric substrate 6. The temperature control module 5 absorbs the heat received from the semiconductor optical modulator 10. The heat absorbed by the temperature control module 5 propagates from the lower substrate 5b of the temperature control module 5 in the negative Z-axis direction via the support block 4 and the metal tube seat 1, dissipating heat to the cooling component (not shown) on the lower surface of the metal tube seat 1.

[0030] Temperature sensor 11 indirectly measures the temperature of semiconductor optical modulation element 10. The measured temperature is fed back to temperature control module 5. If the temperature of semiconductor optical modulation element 10 is higher than the target value, temperature control module 5 cools it; conversely, if the temperature is lower than the target value, it heats it. This stabilizes the temperature of semiconductor optical modulation element 10.

[0031] If the temperature sensor 11 is directly connected to the pin 2d by a wire, the ambient air temperature transmitted from the outside to the metal socket 1 will flow into the temperature sensor 11 through the wire, making it impossible to measure the correct temperature. Therefore, a ceramic block 12 is placed between the temperature sensor 11 and the pin 2d to act as a relay. This reduces the heat flowing into the temperature sensor 11, allowing it to measure the correct temperature. Furthermore, since the temperature sensor 11 and the semiconductor optical modulation element 10 are mounted on the same dielectric substrate 6, temperature correlation is easily matched, and temperature control is convenient.

[0032] The light-receiving element 13 converts the optical signal into an electrical signal (O / E conversion). The electrical signal is transmitted to pin 2f via the connected conductive wire 14l. By providing the light-receiving element 13, although the number of pins passing through the metal socket 1 increases by one, it is possible to monitor the intensity of the back light of the semiconductor optical modulator 10. By feeding back this monitoring result, the drive current of the semiconductor optical modulator 10 can be controlled to make the light output constant.

[0033] Alternatively, the semiconductor optical modulation element 10, temperature sensor 11, and ceramic block 12 can be pre-assembled onto the dielectric substrate 6 to form a semi-finished product, which is then bonded to the temperature control module 5. Therefore, as the bonding material between the temperature control module 5 and the dielectric substrate 6, it is not necessary to use high-melting-point materials such as SnAgCu solder or AuSn solder; instead, thermosetting resins or UV-curing resins can be used. As a result, the manufacturing difficulty is reduced.

[0034] Figure 5 This is a graph comparing the power consumption of the temperature control module in the conventional configuration and the configuration of this embodiment. The heat output of the semiconductor optical modulation element 10 was fixed at 0.2W, and the ambient temperature was varied from -40°C to 95°C. It can be seen that the configuration of this embodiment has a low power consumption of approximately 0.2W.

[0035] As explained above, in this embodiment, a temperature control module 5 is mounted on the side of a support block 4 disposed on a metal tube base 1, and a dielectric substrate 6 on which a semiconductor optical modulation element 10 is mounted is bonded to the temperature control module 5. Therefore, since a second dielectric substrate is not required, costs can be reduced. Furthermore, since the dielectric substrate 6 can be enlarged, the degree of freedom in mounting the dielectric substrate 6 is increased. Additionally, since short conductive wires can be used to connect signal lines and pins disposed on the main surface of the dielectric substrate 6, high-frequency characteristics are improved. Furthermore, since the distance from the temperature control module 5 to the semiconductor optical modulation element 10 is short, heat diffusion is improved, and the heat absorption and dissipation in the temperature control module 5 are improved, thus reducing power consumption. Moreover, since the electrical signal input to the semiconductor optical modulation element 10 is a differential drive method, compared to the conventional single-layer drive method, the voltage amplitude of the signal generator can be reduced, thus reducing the power consumption of the signal generator.

[0036] In conventional structures, due to the second dielectric substrate, signal reflection occurs at the connection point due to impedance mismatch, resulting in reduced bandwidth gain. However, since the second dielectric substrate is not required in this embodiment, there is no signal reflection point, enabling a wider bandwidth than conventional structures.

[0037] There is no secondary medium such as a metal block between the temperature control module 5 and the dielectric substrate 6; instead, the two are directly bonded. Therefore, the distance between the semiconductor optical modulation element 10 and the temperature control module 5 is only the thickness of the dielectric substrate 6. Consequently, the thermal distance from the temperature control module 5 to the semiconductor optical modulation element 10 is short, resulting in improved heat dissipation and reduced power consumption. Furthermore, since the temperature control module 5 and the dielectric substrate 6 are directly bonded, costs can be reduced by decreasing manufacturing processes, time, and the number of components.

[0038] Furthermore, the differential drive signal lines 7a and 7b and pins 2b and 2c on the dielectric substrate 6 are directly connected via conductive wires 14d and 14e, without passing through other dielectric substrates. As a result, there are fewer signal reflection points, and the high-frequency characteristics are improved.

[0039] To seal and fix the pins 2a to 2f to the metal socket 1 via the glass 3, a compression scheme or a matching scheme is generally used. To maintain hermeticity, it is important that the pins 2a to 2f are subjected to equal pressure during sealing. Therefore, it is preferable to arrange the pins 2a to 2f in a circular shape to the metal socket 1. Furthermore, since the sealing performance deteriorates when adjacent pins 2a to 2f are too close together, a certain degree of spacing is required.

[0040] In conventional designs where the temperature control module is joined to the metal socket 1 in a flat position, it occupies an area on the metal socket 1, making it impossible to evenly arrange the pins 2a to 2f and thus failing to achieve airtightness. In this embodiment, since the temperature control module 5 is joined to the side of the support block 4, the area it occupies on the metal socket 1 can be reduced.

[0041] Furthermore, although pins 2a to 2d are arranged on the main surface of the dielectric substrate 6, the two pins 2e used to supply power to the temperature control module 5 are arranged on the back surface of the dielectric substrate 6. Therefore, pins 2a to 2f can be uniformly arranged in a circular shape on the metal socket 1. As a result, the airtightness is improved. In addition, conductive wire 14j connects the metallized part 5d of the temperature control module 5 and the conductor 9 for the temperature control module, and conductive wire 14k connects the conductor 9 for the temperature control module and pin 2e. As a result, the distance in the XY plane from pin 2e to the metallized part 5d is shortened. Therefore, the effect of the torque load applied to the conductive wires 14j and 14k is reduced, and the resistance of the conductive wires 14j and 14k to bending, vibration, and impact is improved.

[0042] If wires are connected to the pins and metallized portion 5d on the main surface of the dielectric substrate 6, excluding the pins 2b and 2c connected to the differential drive signal lines 7a and 7b, the distance in the XY plane from the pin to the metallized portion 5d becomes longer. Therefore, under the influence of torque loads, the conductive wires may bend, leading to contact between the conductive wires and the dielectric substrate 6. Furthermore, under the influence of vibrations and impacts during transport, the conductive wires may detach from the pins. Additionally, it is difficult to directly connect the conductive wires from the pins on the main surface of the dielectric substrate 6 to the metallized portion 5d of the temperature control module 5. Therefore, in this embodiment, a conductor 9 for the temperature control module is provided from the main surface of the dielectric substrate 6 to its upper side. Conductive wire 14j connects the metallized portion 5d of the temperature control module 5 and the conductor 9 for the temperature control module, and conductive wire 14k connects the conductor 9 for the temperature control module and the pin 2e on the back side of the dielectric substrate 6. Therefore, power can be supplied to the temperature control module 5 without using a complex mechanism that involves wire connection devices.

[0043] Due to changes in thermal stress caused by external temperature variations, the emission position and angle of the semiconductor optical modulation element 10 shift. This reduces the optical coupling efficiency of the laser light source device in the optical fiber. Therefore, it is important to design a structure that is less susceptible to changes in thermal stress. In this embodiment, the outer diameters of the dielectric substrate 6 in the X and Z axes are larger than the outer diameters of the upper substrate 5c of the temperature control module 5 in the X and Z axes. This increases the rigidity of the structure, reduces stress on the semiconductor optical modulation element 10, and suppresses breakage of the semiconductor optical modulation element 10. Furthermore, the dielectric substrate 6 can suppress the influence of the deflection of the temperature control module 5. As a result, compared to the case where the outer diameter of the dielectric substrate 6 is smaller than the outer diameter of the upper substrate 5c, the shift in emission position and angle in the positive Y-axis direction is reduced. Additionally, the outer diameter of the upper substrate 5c of the temperature control module 5 can be larger than the outer diameter of the dielectric substrate 6. This improves heat dissipation and heat absorption in the temperature control module 5, thereby reducing power consumption.

[0044] In conventional designs, the grounding of the semiconductor optical modulation element extends from the first dielectric substrate to the second dielectric substrate via conductive wires, and is connected to a metal socket via a metal block supporting the second dielectric substrate. Therefore, the distance is long, resulting in a weaker grounding point (GND) and deteriorating high-frequency characteristics. In contrast, in this embodiment, the grounding conductor 8 of the dielectric substrate 6 is directly connected to the metal socket 1 via conductive wires 14h and 14i, without passing through the second dielectric substrate. This strengthens the grounding point and improves high-frequency characteristics.

[0045] A grounding conductor 8 is provided from the main surface of the dielectric substrate 6 to the back surface in an area that does not contact the differential drive signal lines 7a and 7b or the conductor 9 for the temperature control module. To obtain a ground shared by the semiconductor optical modulation element 10 and the temperature sensor 11, a conductive wire 14h connects the grounding conductor 8 on the main surface of the dielectric substrate 6 to the metal socket 1. However, according to high-frequency simulations, it is difficult to achieve equipotentiality in this way alone, and it is difficult to achieve a wide bandwidth for the frequency response characteristics. Therefore, a conductive wire 14i connects the grounding conductor 8 on the back surface of the dielectric substrate 6 to the metal socket 1. This improves the frequency response characteristics. Since the improvement effect is weak with only one conductive wire 14h or 14i, it is preferable to have two or more.

[0046] Furthermore, when the dielectric substrate 6 comes into contact with the metal socket 1, heat from the outside that is transferred to the metal socket 1 flows through the dielectric substrate 6 into the semiconductor optical modulation element 10 and the temperature sensor 11. Therefore, it is difficult to control the temperature using the temperature control module 5. Thus, it is preferable to prevent the dielectric substrate 6 from contacting the metal socket 1.

[0047] Furthermore, pins 2b and 2c, which are connected to the differential drive signal lines 7a and 7b, have internal lead portions protruding from the upper surface of the metal socket 1. The shorter the length of the internal lead portions, the less inductive the signal, which reduces signal loss caused by reflections at the internal lead portions and improves the passband.

[0048] In addition, in order to obtain the maximum voltage amplitude from the signal generator, a matching resistor can be provided on the main surface of the dielectric substrate 6 and connected in parallel with the semiconductor optical modulation element 10.

[0049] Implementation Method 2

[0050] Figure 6 This is a front perspective view of the semiconductor laser source device according to Embodiment 2. Instead of the semiconductor optical modulation element 10, an MZM (Mach Zehnder Module) type semiconductor optical modulation element 15 is mounted on the main surface of the dielectric substrate 6. The semiconductor optical modulation element 15 is, for example, a laser diode monolithically integrated with a distributed feedback laser diode, two phase modulator sections 16a and 16b, a polarization rotator section 17, and a light-receiving element 13. The phase modulator sections 16a and 16b are Mach-Zehnder type optical modulators.

[0051] Similar to Embodiment 1, differential drive signal lines 7a, 7b, etc., are provided on the main surface of the dielectric substrate 6. Furthermore, the polarization rotator conductor 18 and the light-receiving element conductor 19 are provided on the main surface of the dielectric substrate 6 through Au plating and metallization. Conductive wires 14b and 14c connect one end of the two differential drive signal lines 7a and 7b to the phase modulator sections 16a and 16b of the semiconductor optical modulator 15. Conductive wire 14m connects the polarization rotator section 17 of the semiconductor optical modulator 15 to the polarization rotator conductor 18. Conductive wire 14n connects the polarization rotator conductor 18 to the pin 2g. Conductive wire 14o connects the light-receiving element 13 of the semiconductor optical modulator 15 to the light-receiving element conductor 19. Conductive wire 14p connects the light-receiving element conductor 19 to the pin 2f.

[0052] Since the semiconductor optical modulation element 15 has two phase modulator sections 16a and 16b and a polarization rotator section 17, it would normally be necessary to set one more pin than in Embodiment 1. However, if an additional pin is added to the structure of Embodiment 1 and arranged in a circular shape, the pin spacing becomes too narrow, making it impossible to ensure hermeticity and thus failing to guarantee mass production.

[0053] Therefore, in this embodiment, pin 2a is positioned at the center of the metal socket 1. Since pressure can be applied evenly at the center, the same airtightness as in Embodiment 1 can be maintained. Furthermore, in conventional configurations where the temperature control module is joined to the center of the metal socket in a flat position, the pin cannot be positioned at the center of the metal socket, resulting in deteriorated airtightness.

[0054] The outer diameter of the MZM-type semiconductor optical modulator 15 is several millimeters, which is several times the outer diameter of the electric field absorption type optical modulator in Embodiment 1. Therefore, in the conventional structure where a second dielectric substrate exists on the socket, mounting the MZM-type semiconductor optical modulator 15 is difficult. To mount the MZM-type semiconductor optical modulator, it is necessary to increase the light emission direction by several millimeters, thereby increasing the outer diameter of the laser source device. Along with this, the distance from the temperature control module 5 to the semiconductor optical modulator 15 increases, the heat absorption and dissipation performance of the temperature control module 5 deteriorates, and the temperature control module 5 needs to be upgraded to a higher performance. In addition, since the distance from the pin to the semiconductor optical modulator also increases, the high-frequency characteristics deteriorate due to the extension of the high-frequency line.

[0055] In contrast, in this embodiment, the mounting freedom of the dielectric substrate 6 is increased compared to the conventional embodiment. Therefore, the MZM-type semiconductor optical modulation element 15 can be mounted on the main surface of the dielectric substrate 6 without increasing the outer diameter of the laser light source device. The distance from the temperature control module 5 to the semiconductor optical modulation element 15 is equal to the thickness of the dielectric substrate 6, which is very close. Therefore, the heat absorption and dissipation performance is as good as in Embodiment 1, and there is no need for high-performance temperature control module 5. In addition, there is no need for the extension of high-frequency lines, and the high-frequency characteristics are not degraded.

[0056] Furthermore, the light-receiving element 13 is generally integrated into the MZM-type semiconductor optical modulation element 15, but it can also be installed separately as in Embodiment 1. Other structures and effects are the same as in Embodiment 1.

[0057] Implementation Method 3

[0058] Figure 7 This is a front perspective view of the semiconductor laser source device according to Embodiment 3. Lens 20, optical element 21, and block 22 are mounted on the main surface of dielectric substrate 6. Light receiving element 13 is mounted on the side of block 22. Instead of semiconductor light modulation element 10, semiconductor light modulation element 23 is mounted on the main surface of dielectric substrate 6.

[0059] The semiconductor optical modulation element 23 has a semiconductor optical amplifier (SOA) that amplifies the intensity of the laser. Therefore, higher light output can be obtained. Although the overall length of the semiconductor optical modulation element 23 with the optical amplifier is longer, in this embodiment, since the mounting space on the main surface of the dielectric substrate 6 is large, it is not necessary to change the structure of the dielectric substrate 6, which is an important factor in high cost or bandwidth degradation.

[0060] The lens 20 and optical element 21 are made of glass such as SiO2. The lens 20 and optical element 21 are bonded to the dielectric substrate 6 by bonding materials such as epoxy resin adhesives. When using epoxy resin, after temporary curing by ultraviolet irradiation immediately after bonding, the bonding is achieved by heat curing through a heat treatment process.

[0061] Lens 20 parallelizes or focuses the laser emitted from semiconductor optical modulation element 23 toward the positive Z-axis. Optical element 21 separates a portion of the laser emitted from semiconductor optical modulation element 23. Light receiving element 13 converts the separated laser into an electrical signal.

[0062] In conventional designs, the use of a second dielectric substrate makes it difficult to mount the light-receiving element 13. Mounting the lens 20, optical element 21, and light-receiving element 13 complicates the design, increases the outer diameter of the laser source device, and reduces reliability in terms of intensity and heat distribution. In contrast, in this embodiment, the mounting freedom of the dielectric substrate 6 is increased compared to conventional designs, allowing the lens 20, optical element 21, block 22, and light-receiving element 13 to be mounted on the main surface of the dielectric substrate 6 without increasing the outer diameter of the laser source device.

[0063] Block 22 is, for example, an AlN substrate, with conductors 22a and 22b separated from each other on its surface. The back electrode of the light-receiving element 13 is bonded to conductor 22a of block 22 by solder or the like. The surface electrode of the light-receiving element 13 is bonded to conductor 22b by conductive wire 14q. This bonding is done in a process different from the assembly process of the laser light source device, and a semi-finished product is pre-made and bonded to the main surface of the dielectric substrate 6 simultaneously with the bonding of the semiconductor light modulation element 23, etc. This reduces the manufacturing difficulty compared to not making a semi-finished product. After bonding the semi-finished product to the main surface of the dielectric substrate 6, conductor 22b is connected to pin 2f by conductive wire 14r. This allows the electrical signal converted by the light-receiving element 13 to be sent to the negative Z-axis direction of pin 2f. Other structures and effects are the same as in Embodiment 1.

[0064] Implementation Method 4

[0065] Figure 8 This is a schematic diagram showing the semiconductor laser source device according to Embodiment 4. The lens cover 24 is joined to the metal socket 1 of any one of the semiconductor laser source devices in Embodiments 1 to 3. The lens cover 24 is an airtight cover for sealing the support block 4, temperature control module 5, dielectric substrate 6, semiconductor optical modulation element 10, and temperature sensor 11 mounted on the metal socket 1. Therefore, it can improve moisture resistance and resistance to external interference. The lens of the lens cover 24 is, for example, made of glass, specifically SiO2, which causes the laser emitted from the semiconductor optical modulation element 10 to be substantially focused or collimated. For example, when the lens cover 24 is joined to Embodiment 3, after the laser from the semiconductor optical modulation element 23 with a large extension angle is collimated by the lens 20, the collimated light is focused by the lens cover 24 and incident into the optical fiber. Furthermore, in Embodiments 1 and 2, collimation is not performed; instead, the light is directly focused and incident into the optical fiber.

[0066] Explanation of reference numerals in the attached figures

[0067] 1...Metal socket; 2a-2g...Pin; 4...Support block; 5...Temperature control module; 5a...Thermoelectric element; 5b...Lower substrate; 5c...Upper substrate; 5d...Metallization; 6...Dielectric substrate; 7a, 7b...Differential drive signal lines; 8...Ground conductor; 10, 15, 23...Semiconductor optical modulation element; 11...Temperature sensor; 12...Ceramic block; 13...Light receiving element; 14a-14r...Conductive wire; 21...Optical element; 22...Block; 20...Lens; 24...With lens cover.

Claims

1. A semiconductor laser source device, characterized in that, have: Metal tube socket; Pin 1, pin 2, and pin 3 pass through the metal socket; A support block is disposed on the metal tube base; A temperature control module is mounted on the side of the support block and has a lower substrate, an upper substrate, and a plurality of thermoelectric elements sandwiched between the upper substrate and the lower substrate. The dielectric substrate has its back side bonded to the upper substrate of the temperature control module; Two differential drive signal lines are disposed on the main surface of the dielectric substrate; A semiconductor optical modulation element is mounted on the main surface of the dielectric substrate; A temperature sensor is mounted on the main surface of the dielectric substrate; The first conductive wire connects one end of the differential drive signal line and the semiconductor optical modulation element; The second conductive wire connects the other end of the differential drive signal line to the first pin; The third conductive wire connects the temperature sensor and the second pin; as well as The fourth conductive wire connects the temperature control module and the third pin. The first pin and the second pin are configured on the main surface side of the dielectric substrate. The third pin is located on the back side of the dielectric substrate. The lower substrate has a protrusion that extends upwards compared to the upper substrate. A metallized portion for supplying electricity to the thermoelectric element is provided on the protrusion. The temperature control module is disposed from the main surface of the dielectric substrate to the upper side surface using a conductor. The fourth conductive wire includes: a conductive wire that connects the temperature control module disposed on the upper side of the dielectric substrate to the third pin, and a conductive wire that connects the temperature control module disposed on the main surface of the dielectric substrate to the metallization portion.

2. The semiconductor laser source device according to claim 1, characterized in that, The other end of the differential drive signal line is directly connected to the first pin via the second conductive wire.

3. The semiconductor laser source device according to claim 1 or 2, characterized in that, The outer diameter of the dielectric substrate is larger than the outer diameter of the upper substrate.

4. The semiconductor laser source device according to claim 1 or 2, characterized in that, It also includes a ceramic block mounted on the dielectric substrate and having a conductive film disposed thereon. The third conductive wire has: a conductive wire connecting the conductor film and the temperature sensor, and a conductive wire connecting the conductor film and the second pin.

5. The semiconductor laser source device according to claim 1 or 2, characterized in that, The modulator section of the semiconductor optical modulation element is composed of multiple electric field absorption type optical modulators.

6. The semiconductor laser source device according to claim 1 or 2, characterized in that, The phase modulator section of the semiconductor optical modulation element is a Mach-Zehnder type optical modulator.

7. The semiconductor laser source device according to claim 1 or 2, characterized in that, It includes a lens mounted on the main surface of the dielectric substrate, which parallelizes or focuses the laser emitted from the semiconductor optical modulation element.

8. The semiconductor laser source device according to claim 1 or 2, characterized in that, It also includes a light-receiving element that converts a portion of the laser emitted from the semiconductor optical modulation element into an electrical signal.

9. The semiconductor laser source device according to claim 8, characterized in that, It also has: An optical element, mounted on the main surface of the dielectric substrate, separates a portion of the laser light emitted from the semiconductor optical modulation element; and A block, mounted on the main surface of the dielectric substrate. The light-receiving element is mounted on the side of the block and converts a portion of the laser light separated by the optical element into an electrical signal.

10. The semiconductor laser source device according to any one of claims 1, 2, and 9, characterized in that, The semiconductor optical modulation element has an optical amplifier that amplifies the intensity of the laser.

11. The semiconductor laser source device according to any one of claims 1, 2, and 9, characterized in that, An airtight sealing cap is fitted to the metal tube seat.

12. A semiconductor laser source device, characterized in that, have: Metal tube socket; Pin 1, pin 2, and pin 3 pass through the metal socket; A support block is disposed on the metal tube base; A temperature control module is mounted on the side of the support block and has a lower substrate, an upper substrate, and a plurality of thermoelectric elements sandwiched between the upper substrate and the lower substrate. The dielectric substrate has its back side bonded to the upper substrate of the temperature control module; Two differential drive signal lines are disposed on the main surface of the dielectric substrate; A semiconductor optical modulation element is mounted on the main surface of the dielectric substrate; A temperature sensor is mounted on the main surface of the dielectric substrate; The first conductive wire connects one end of the differential drive signal line and the semiconductor optical modulation element; The second conductive wire connects the other end of the differential drive signal line to the first pin; The third conductive wire connects the temperature sensor and the second pin; A fourth conductive wire connects the temperature control module and the third pin; and A grounding conductor is disposed on the dielectric substrate and directly connected to the metal tube socket via a conductive wire. The grounding conductor is disposed on the main surface and the back surface of the dielectric substrate, and is connected to the metal tube socket through conductive wires, respectively.

13. The semiconductor laser source device according to claim 12, characterized in that, The other end of the differential drive signal line is directly connected to the first pin via the second conductive wire.

14. The semiconductor laser source device according to claim 12 or 13, characterized in that, The outer diameter of the dielectric substrate is larger than the outer diameter of the upper substrate.

15. The semiconductor laser source device according to claim 12 or 13, characterized in that, It also includes a ceramic block mounted on the dielectric substrate and having a conductive film disposed thereon. The third conductive wire has: a conductive wire connecting the conductor film and the temperature sensor, and a conductive wire connecting the conductor film and the second pin.

16. The semiconductor laser source device according to claim 12 or 13, characterized in that, The modulator section of the semiconductor optical modulation element is composed of multiple electric field absorption type optical modulators.

17. The semiconductor laser source device according to claim 12 or 13, characterized in that, The phase modulator section of the semiconductor optical modulation element is a Mach-Zehnder type optical modulator.

18. The semiconductor laser source device according to claim 12 or 13, characterized in that, It includes a lens mounted on the main surface of the dielectric substrate, which parallelizes or focuses the laser emitted from the semiconductor optical modulation element.

19. The semiconductor laser source device according to claim 12 or 13, characterized in that, It also includes a light-receiving element that converts a portion of the laser emitted from the semiconductor optical modulation element into an electrical signal.

20. The semiconductor laser source device according to claim 19, characterized in that, It also has: An optical element, mounted on the main surface of the dielectric substrate, separates a portion of the laser light emitted from the semiconductor optical modulation element; and A block, mounted on the main surface of the dielectric substrate. The light-receiving element is mounted on the side of the block and converts a portion of the laser light separated by the optical element into an electrical signal.

21. The semiconductor laser source device according to any one of claims 12, 13, and 20, characterized in that, The semiconductor optical modulation element has an optical amplifier that amplifies the intensity of the laser.

22. The semiconductor laser source device according to any one of claims 12, 13, and 20, characterized in that, An airtight sealing cap is fitted to the metal tube seat.

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