Optical module and optical transceiver

Abstract

An optical module according to the present disclosure comprises: a stem having a main surface and a surface opposite the main surface; a lead pin penetrating the stem from the main surface to the surface opposite the main surface; a temperature control module mounted on the main surface of the stem; a dielectric substrate mounted on the opposite side of the temperature control module from the main surface of the stem; and a semiconductor optical integrated element mounted on the opposite side of the dielectric substrate from the temperature control module and having a semiconductor laser and an optical amplifier.

Description

Optical Modules and Transceivers

[0001] The present disclosure relates to an optical module and an optical transceiver.

[0002] Patent Document 1 discloses an optical module including a conductive stem having a first surface and a second surface and a plurality of through holes penetrating between the first surface and the second surface, and a plurality of lead pins. The lower surface of a thermoelectric cooler is fixed to the first surface of the conductive stem. A submount substrate having a wiring pattern on the surface opposite the thermoelectric cooler is fixed to the upper surface of the thermoelectric cooler. Signal wires electrically connect the tip surfaces of the signal lead pins to the wiring pattern on the submount substrate. A photoelectric device is mounted on the submount. The photoelectric device is a laser that emits light parallel to the first surface. The light emitted from the photoelectric device is reflected by a mirror in a direction intersecting the first surface.

[0003] Japanese Patent Application Laid-Open No. 2022-143753

[0004] In a CAN-type optical module such as that disclosed in Patent Document 1, the optoelectronic device does not have a function for amplifying modulated light. This can lead to the risk of insufficient optical output. Furthermore, adding an amplification function requires securing a mounting area along with the expansion of the semiconductor optical integrated device, and adding a power supply line. However, securing the mounting area is difficult with the structure disclosed in Patent Document 1.

[0005] An object of the present disclosure is to provide an optical module and an optical transceiver that can obtain high optical output power.

[0006] The optical module according to the present disclosure comprises a stem having a main surface and a surface opposite to the main surface, a lead pin penetrating the stem from the main surface to the surface opposite to the main surface, a temperature control module mounted on the main surface of the stem, a dielectric substrate mounted on the temperature control module on the side opposite to the main surface of the stem, and a semiconductor optical integrated element mounted on the dielectric substrate on the side opposite to the temperature control module, the semiconductor optical integrated element having a semiconductor laser and an optical amplifier.

[0007] In the optical module according to the present disclosure, a high optical output can be obtained by the optical amplifier.

[0008] FIG. 1 is a perspective view of an optical module according to a first embodiment. FIG. 2 is a cross-sectional view of a semiconductor optical integrated element according to the first embodiment. FIG. 3 is a front view of an optical module according to the first embodiment. FIG. 4 is a plan view of an optical module according to the first embodiment. FIG. 5 is a diagram explaining a connection state of a capacitor and a resistor according to the first embodiment. FIG. 6 is a plan view of an optical module according to a second embodiment. FIG. 7 is a perspective view of an optical module according to a third embodiment. FIG. 8 is a cross-sectional view of a semiconductor optical integrated element according to a fourth embodiment. FIG. 9 is a perspective view of an optical module according to the fourth embodiment. FIG. 10 is a diagram explaining an optical element according to the first embodiment. FIG. 11 is a diagram explaining an optical element according to a fifth embodiment. FIG. 12 is a diagram explaining a light-receiving element according to a sixth embodiment. FIG. 13 is a cross-sectional view showing a state in which an optical module according to a seventh embodiment and a receptacle are connected. FIG. 14 is a perspective view of an optical transceiver according to the seventh embodiment.

[0009] An optical module and an optical transceiver according to each embodiment will be described with reference to the drawings. The same or corresponding components are designated by the same reference numerals, and repeated description may be omitted.

[0010] First Embodiment. FIG. 1 is a perspective view of an optical module 100 according to a first embodiment. The optical module 100 includes a stem 1 having a main surface and a surface opposite the main surface. The stem 1 is formed from metal. The stem 1 is a metal material, for example, a material with high thermal conductivity, such as Cu, plated with Au, and is also called a stem base. The stem 1 is circular in plan view and formed in a plate shape. The stem 1 fixes a temperature control module 5 (described later) and other components, and also serves to dissipate heat absorbed by the temperature control module 5 to the side of the stem 1 and to a cooling member (not shown) on the negative side of the Z axis. The Z axis is perpendicular to the main surface of the stem 1.

[0011] A plurality of lead pins penetrate the stem 1 from the main surface to the surface opposite the main surface. The plurality of lead pins include a DC power supply lead pin 2 and an RF power supply lead pin 3. To fix the lead pins to the stem 1, glass is generally applied to the through holes in the stem 1. A material with a low dielectric constant is used for the RF power supply lead pin 3, which transmits electrical signals, so that it has the same impedance as the signal generator. This is because impedance mismatching causes multiple reflections of the signal, degrading the frequency response characteristics and making high-speed modulation difficult.

[0012] A raised portion 4 is formed on the main surface of the stem 1. The RF power supply lead pin 3 is provided on the raised portion 4 and protrudes from the raised portion 4. Because the glass is provided up to near the upper surface of the raised portion 4, the portion of the RF power supply lead pin 3 that protrudes from the glass surface can be shortened. The longer the portion of the RF power supply lead pin 3 that protrudes from the glass surface, the greater the impedance mismatch and the more likely the high-frequency characteristics are to deteriorate. In this way, the raised portion 4 can improve the high-frequency characteristics.

[0013] In order to seal and fix the DC power supply lead pins 2 and the RF power supply lead pins 3 to the stem 1 with glass, a compression method or a matching method is generally used. To maintain airtightness, it is important that the multiple lead pins are under equal pressure during sealing. For this reason, it is desirable that the multiple lead pins are arranged in a circular pattern on the stem 1. Furthermore, if the lead pins are too close together, the sealing performance deteriorates. For this reason, a certain distance is required between the lead pins. In this embodiment, as an example, seven lead pins are arranged in a circular pattern at equal intervals.

[0014] A temperature control module 5 is mounted on the main surface of the stem 1. The temperature control module 5 is composed of, for example, multiple blocks and an upper substrate 5a and a lower substrate 5b that sandwich the multiple blocks. The blocks are made of, for example, BiTe (bismuth telluride). The upper substrate 5a and the lower substrate 5b are made of, for example, AlN (aluminum nitride). The temperature control module 5 dissipates heat received from the semiconductor optical integrated device 10 mounted on the upper substrate 5a from the lower substrate 5b to the stem 1 side.

[0015] The stem 1 is bonded to the lower substrate 5b of the temperature control module 5. As a bonding material, for example, solder using a material such as AuSn, or an adhesive such as resin is used.

[0016] The oscillation wavelength of the semiconductor optical integrated device 10 changes with temperature changes. For this reason, it is desirable to maintain a constant temperature of the semiconductor optical integrated device 10. The temperature control module 5 cools the semiconductor optical integrated device 10 when the temperature rises, and generates heat when the temperature drops. This makes it possible to maintain a constant temperature of the semiconductor optical integrated device 10.

[0017] A dielectric substrate 6 is mounted on the temperature control module 5 on the side opposite the main surface of the stem 1. Specifically, the dielectric substrate 6 is mounted on the surface of the upper substrate 5a of the temperature control module 5. The dielectric substrate 6 is plate-shaped. The dielectric substrate 6 is formed, for example, by applying Au plating and metallization to the surface of a ceramic material such as aluminum nitride (AlN). The dielectric substrate 6 fixes the semiconductor optical integrated device 10 and also serves to dissipate heat generated in the semiconductor optical integrated device 10 to the cooling member on the negative Z-axis side of the stem 1. In addition to this heat transfer function, the dielectric substrate 6 also serves as an electrical insulator. The dielectric substrate 6 is also located higher in the positive Z-axis direction than the protruding portion 4. This prevents interference between the dielectric substrate 6 and the protruding portion 4.

[0018] 2 is a cross-sectional view of a semiconductor optical integrated device 10 according to the first embodiment. The semiconductor optical integrated device 10 is mounted on the dielectric substrate 6 on the side opposite the temperature control module 5. The semiconductor optical integrated device 10 includes a semiconductor laser 7, an optical modulator 8, and an optical amplifier 9. The semiconductor laser 7, the optical modulator 8, and the optical amplifier 9 are formed adjacent to each other but are electrically independent. The semiconductor laser 7, the optical modulator 8, and the optical amplifier 9 are electrically insulated from each other by a semi-insulating substrate such as Fe-doped InP, and current can be passed through them independently, providing high current controllability. The semiconductor laser 7, the optical modulator 8, and the optical amplifier 9 share a common GND.

[0019] The semiconductor optical integrated device 10 emits laser light parallel to the main surface of the stem 1. The main ray of the laser light emitted from the front end face of the semiconductor optical integrated device 10 is emitted obliquely with respect to the main axis of the semiconductor optical integrated device 10. Here, the main axis of the semiconductor optical integrated device 10 is the direction along the long side of the semiconductor optical integrated device 10, which is the Y-axis direction in FIG.

[0020] 1, a high-frequency transmission line 6a, which is metallized for RF power supply, is formed on the dielectric substrate 6. One end of the high-frequency transmission line 6a is connected to the optical modulator 8 by a conductive wire, and the other end is connected to the RF power supply lead pin 3 by a conductive wire. The high-frequency transmission line 6a may be connected to the RF power supply lead pin 3 by solder or a conductive adhesive. The shorter the conductive wire, the smaller the inductance component, resulting in better high-frequency characteristics.

[0021] The high-frequency transmission line 6a is a microstrip or coplanar line and has an impedance equivalent to the output impedance of the signal generator. When an electrical signal is input to the RF power feed lead pin 3, the electrical signal is applied to the optical modulator 8 via the conductive wire and the high-frequency transmission line 6a. The electrical signal input to the RF power feed lead pin 3 is electromagnetically coupled to the stem 1 and the protrusion 4, and the GND electrode pattern of the stem 1, the protrusion 4, and the dielectric substrate 6 act as an AC ground.

[0022] In this embodiment, an optical amplifier 9 is formed on the semiconductor optical integrated device 10. This allows for high optical output. However, forming the optical amplifier 9 increases the overall length of the semiconductor optical integrated device 10. For example, when an optical amplifier is provided in an optical module such as that described in Patent Document 1, the submount substrate must be enlarged. In particular, in Patent Document 1, in order to improve high-frequency characteristics, the mounting area where the thermoelectric cooler is mounted is lower than the reference area where multiple lead pins are arranged. This results in a small mounting area. In this case, if the submount substrate is enlarged, the area that protrudes from the temperature control module increases, and the thermal resistance between the submount substrate and the temperature control module increases. This may make it difficult to apply the optical amplifier 9.

[0023] In contrast, in this embodiment, the surface of the stem 1 from which the lead pins protrude and the surface on which the temperature control module 5 is provided are at the same height. This allows a large mounting space to be secured. Therefore, even when a large semiconductor optical integrated device 10 on which an optical amplifier 9 is formed is provided, the area protruding from the upper substrate 5a of the dielectric substrate 6 can be reduced. This allows the thermal resistance between the dielectric substrate 6 and the temperature control module 5 to be suppressed. Furthermore, in this embodiment, the protruding portion 4 allows the portion of the RF power supply lead pin 3 that protrudes from the glass surface to be shortened. Furthermore, the conductive wire connected to the RF power supply lead pin 3 can be shortened. This allows a large mounting space to be secured while improving the high-frequency characteristics.

[0024] The thermistor 12 indirectly monitors the temperature of the semiconductor optical integrated device 10. The thermistor 12 feeds back the monitored temperature to the temperature control module 5, and is configured to cool the semiconductor optical integrated device 10 if the temperature is higher than the target value, and to generate heat if the temperature is lower. This makes it possible to stabilize the temperature of the semiconductor optical integrated device 10. The thermistor 12 may be mounted on the surface of either the upper substrate 5a or the dielectric substrate 6.

[0025] A GND electrode pattern 6b is formed on the surface of the dielectric substrate 6 and is connected to the surface of the stem via a conductive wire 30. A GND electrode pattern 6c, which is GND metallization, is formed on the side surface of the dielectric substrate 6 and is electrically connected to the front and back surfaces of the dielectric substrate 6 and the surface electrode patterns of the upper substrate 5a.

[0026] The GND electrode pattern 6c is connected to the side of the protrusion 4 via a conductive wire 31. This strengthens the GND of the dielectric substrate 6 and stabilizes the potential. Therefore, high-frequency characteristics can be improved. Furthermore, if the upper substrate 5a is made of a ceramic material like the dielectric substrate 6, the potential of the upper substrate 5a becomes unstable, making electromagnetic field resonance more likely to occur. For this reason, it is desirable to connect a conductive wire between the surface electrode of the upper substrate 5a and the stem 1. However, if the number of conductive wires for GND connection is increased, the amount of heat transferred from the stem 1 via the conductive wires increases when the environmental temperature changes. This increases the amount of heat absorbed by the temperature control module 5, potentially increasing power consumption. Therefore, it is preferable to reduce the number of conductive wires if possible.

[0027] The potential of the GND of the back surface of the dielectric substrate 6 and the GND of the upper substrate 5a is easily unstable because they are far from the GND of the stem 1. In order to strengthen the GND, a through via may be provided in the dielectric substrate 6, and the GND electrodes on the front and back surfaces of the dielectric substrate 6 may be electrically connected by the through via.

[0028] An optical element 13 is also mounted on the upper substrate 5a. The optical element 13 reflects the laser light perpendicular to the main surface of the stem 1. The main ray of the laser light is emitted in a direction oblique to the main axis of the semiconductor optical integrated device 10. The optical element 13 is oriented obliquely to the main axis of the semiconductor optical integrated device 10 so as to receive the main ray of the semiconductor optical integrated device 10. The optical element 13 reflects a portion of the light intensity of the laser light emitted from the semiconductor optical integrated device 10 in a direction perpendicular to the main surface of the stem 1, and transmits a portion of the light intensity.

[0029] The material of the optical element 13 is, for example, glass made of SiO2. The optical element 13 is bonded to the upper substrate 5a. For example, an epoxy resin adhesive is used as the bonding material. The epoxy resin is temporarily hardened by ultraviolet light irradiation immediately after bonding, and then thermally hardened through a heat treatment process. This completes the bonding.

[0030] A support block 14 is mounted on the main surface of the stem 1, on the rear side of the optical element 13. Electrode patterns are formed on the front and side surfaces of the support block 14. A light-receiving element 15 that receives laser light transmitted by the optical element 13 is mounted on the GND surface of the support block 14. In other words, the light-receiving element 15 is disposed on the opposite side of the optical element 13 from the semiconductor optical integrated element 10. The support block 14 is formed of a ceramic material, for example, aluminum nitride (AlN).

[0031] The optical signal received by the light-receiving element 15 is O / E converted into an electrical signal. The electrical signal is transmitted to the DC power supply lead pin 2 via the conductive wire and the electrode pattern formed on the support block 14. This makes it possible to monitor the intensity of light emitted from the semiconductor optical integrated element 10. Therefore, the drive current to the semiconductor laser 7 and the optical amplifier 9 can be controlled so that the optical output intensity is constant.

[0032] In a structure such as that of Patent Document 1, which has a small mounting area, it is expected that it will be difficult to secure space for mounting a light-receiving element. Furthermore, in the structure of Patent Document 1, lead pins must be placed in a reference area, which is a protrusion provided on the conductive stem. Therefore, even if an optical amplifier or a light-receiving element is to be provided, it may be difficult to secure space for adding lead pins connected to these. In contrast, in the present embodiment, a large mounting space is secured, making it possible to provide an optical module 100 equipped with an optical amplifier 9 and a function for monitoring the intensity of emitted light.

[0033] FIG. 3 is a front view of the optical module 100 according to the first embodiment. FIG. 3 shows a state in which the cap 16 is joined to the stem 1. The cap 16 has a lens 17. The lens 17 is made of glass, for example, SiO2. The lens 17 has the function of substantially focusing or collimating the laser light emitted from the semiconductor optical integrated device 10 and reflected by the optical element 13 in a direction perpendicular to the main surface of the stem 1. The configuration shown in FIG. 3 can ensure the airtightness of the structure mounted on the stem 1, and can improve moisture resistance and resistance to external disturbances.

[0034] Fig. 4 is a plan view of the optical module 100 according to the first embodiment. Fig. 5 is a diagram illustrating the connection state of the capacitor and resistor according to the first embodiment. The connection of the capacitor and resistor will be explained using Figs. 4 and 5. The DC power supply lead pins 2a, 2d, 2e, and 2f are connected to a common GND. The anode and cathode of the temperature control module 5 are connected to the DC power supply lead pins 2b and 2c, respectively, and are independent of the other lead pins.

[0035] The optical module 100 includes a capacitor 20 that connects the semiconductor laser 7 to GND. The capacitor 20 is mounted on the surface electrode pattern of the upper substrate 5a, which is GND. The capacitor 20 connects the DC power supply lead pin 2f to the anode of the semiconductor laser 7 via a conductive wire. The capacitor 20 can cut power supply noise. Note that the capacitor 20 may be mounted on the surface of any of the stem 1, the DC power supply lead pin 2, or the dielectric substrate 6.

[0036] The optical module 100 may include a matching resistor 11 connected in parallel with the optical modulator 8. This allows the maximum voltage amplitude from the signal generator to be obtained. The matching resistor 11 is provided, for example, on the dielectric substrate 6 and connected to the optical modulator 8 by a conductive wire.

[0037] The optical module 100 may include a capacitor 21 connected in parallel with the optical modulator 8. The capacitor 21 is mounted on the dielectric substrate 6. The capacitor 21 and the matching resistor 11 are connected in series. The series circuit formed by the capacitor 21 and the matching resistor 11 is connected in parallel with the optical modulator 8. The RF power supply lead pin 3, the high-frequency transmission line 6a on the dielectric substrate 6, the optical modulator 8, the matching resistor 11, and the capacitor 21 are connected via conductive wires. The capacitor 21 is connected to the electrode pad of the matching resistor 11 by a conductive wire. The capacitor 21 enables an AC coupling method in which the DC component flowing through the matching resistor 11 is cut off.

[0038] The optical module 100 includes a capacitor 22 that connects the optical amplifier 9 to GND. The capacitor 22 is mounted on the main surface of the stem 1. The capacitor 22 connects the DC power supply lead pin 2e and the anode of the optical amplifier 9 via a conductive wire. The capacitor 22 can cut power supply noise. Note that the capacitor 22 may be mounted on any one of the surfaces of the DC power supply lead pin 2, the upper substrate 5a, or the dielectric substrate 6.

[0039] The optical module 100 may also include a protective resistor 19 connected in parallel with the optical modulator 8. The protective resistor 19 has a resistance greater than that of the matching resistor 11, preferably about 1 kΩ, for example. If a capacitor 21 is connected between the matching resistor 11 and GND, the optical modulator 8 may become more likely to charge up, potentially increasing the likelihood of failure. Therefore, the protective resistor 19 may be connected in parallel with the optical modulator 8 and the series circuit formed by the capacitor 21 and the matching resistor 11. Because the resistance of the protective resistor 19 is greater than that of the matching resistor 11, current flows through the protective resistor 19 when a surge is input. This prevents failure of the optical modulator 8.

[0040] In the present embodiment, an example has been described in which the semiconductor optical integrated device 10 includes the optical modulator 8. However, the present invention is not limited to this, and the semiconductor optical integrated device 10 may not include the optical modulator 8 as long as it includes the semiconductor laser 7 and the optical amplifier 9.

[0041] The above-described modifications can be applied as appropriate to the optical modules and optical transceivers according to the following embodiments. Note that the optical modules and optical transceivers according to the following embodiments have many points in common with the first embodiment, so the following description will focus on the differences from the first embodiment.

[0042] Second Embodiment. FIG. 6 is a plan view of an optical module 200 according to a second embodiment. When mounting the temperature control module 5, dielectric substrate 6, and semiconductor optical integrated device 10, care must be taken to avoid interference with the DC power supply lead pin 2 and the raised portion 4. It is also necessary to ensure a mounting area for the cap 16 and to ensure that the principal ray of the laser light reflected by the optical device 13 is positioned near the center of the stem 1. In the first embodiment, these factors are taken into consideration when arranging the components as shown in FIG. 4. In contrast, in the first embodiment, the sides of the temperature control module 5 and the sides of the dielectric substrate 6 are aligned in the same direction. In this case, the portion of the dielectric substrate 6 on which the semiconductor optical integrated device 10 is mounted extends slightly beyond the temperature control module 5. This narrows the heat radiation area from the semiconductor optical integrated device 10, increasing thermal resistance and potentially increasing the power consumption of the temperature control module 5.

[0043] In contrast, in this embodiment, the temperature control module 5 is tilted with respect to the major axis of the semiconductor optical integrated device 10 when viewed from a direction perpendicular to the main surface of the stem 1. In other words, the sides of the temperature control module 5 are tilted with respect to the Y-axis. The temperature control module 5 faces, for example, in the same direction as the optical element 13. This allows the temperature control module 5 to be placed directly below the semiconductor optical integrated device 10. This ensures a wide heat radiation area and reduces the power consumption of the temperature control module 5.

[0044] Third Embodiment. FIG. 7 is a perspective view of an optical module 300 according to a third embodiment. By mounting the temperature control module 5 at an angle relative to the semiconductor optical integrated device 10 as in the second embodiment, the distance between the corners of the temperature control module 5 and the cap 16 is increased. This allows the temperature control module 5 to be larger than in the first embodiment. This allows all of the capacitors 20, 21, and 22 to be mounted on the upper substrate 5a of the temperature control module 5. In this embodiment, the capacitors 20, 21, and 22 are mounted side by side on the side opposite the main surface of the stem 1 of the temperature control module 5. This aligned arrangement of the capacitors 20, 21, and 22 allows the capacitors 20, 21, and 22 to be transported together and mounted in a single process. This reduces takt time. Furthermore, when capacitors are mounted individually, solder pools after mounting can affect the mounting of the next capacitor, resulting in poor bonding performance. In this embodiment, by transporting the capacitors 20, 21, and 22 together, component tilt and other issues are eliminated, improving bonding performance.

[0045] If possible, the capacitors 20, 21, and 22 may be arranged side by side on the temperature control module 5 even in the arrangement of the temperature control module 5 and the semiconductor optical integrated device 10 as in the first embodiment.

[0046] Fourth Embodiment. FIG. 8 is a cross-sectional view of a semiconductor optical integrated device 410 according to a fourth embodiment. In general, a semiconductor laser device has an active layer formed parallel to the substrate and emits light parallel to the substrate. In contrast, in the semiconductor optical integrated device 410 of this embodiment, the front end face of the waveguide 40 is formed at a 45-degree angle with respect to the substrate 41. A mirror 42 that totally reflects light is formed on the front end face. This allows laser light to be emitted perpendicular to the substrate 41. In other words, the mirror 42 reflects the laser light from the semiconductor optical integrated device 410 perpendicular to the main surface of the stem 1. This eliminates the need for the optical element 13, thereby reducing material costs. The configuration in which the waveguide 40 is formed parallel to the top surface of the substrate 41 is the same in the first to third embodiments.

[0047] 9 is a perspective view of an optical module 400 according to the fourth embodiment. According to this embodiment, the light-emitting point of the semiconductor optical integrated device 410 can be moved closer to the center of the stem 1. This increases the bonding area between the temperature control module 5 and the dielectric substrate 6, thereby reducing thermal resistance. This reduces the power consumption of the temperature control module 5.

[0048] 8, a light receiving unit 43 for monitoring the intensity of the laser light reflected by a mirror 42 may be provided directly above the front end face of the semiconductor optical integrated device 410. In this case, there is no need to mount the support block 14 and the light receiving device 15. This reduces the cost of components and makes it easier to manufacture the optical module 400.

[0049] Furthermore, the reflectance of the mirror 42 may be set to about 99%, allowing a portion of the light intensity to be transmitted and the laser light to be emitted parallel to the substrate 41. In this case, as shown in Fig. 9, the light receiving element 15 may be disposed in front of the semiconductor optical integrated element 410, and the intensity of the transmitted laser light may be monitored by the light receiving element 15. In this case, it is not necessary to mount the light receiving section 43 on the semiconductor optical integrated element 410, and the semiconductor optical integrated element 410 can be easily manufactured.

[0050] 10 is a diagram illustrating the optical element 13 according to the first embodiment. In the first to third embodiments, the optical element 13 is mounted on the upper substrate 5a of the temperature control module 5. This increases the distance between the light-emitting point of the semiconductor optical integrated device 10 and the optical element 13, and the optical path to the lens 17 becomes longer. As a result, the beam 18, which has spread widely, does not fit within the effective diameter of the lens 17, causing vignetting, which may reduce the optical coupling efficiency in the optical fiber (not shown).

[0051] 11 is a diagram illustrating an optical element 513 according to a fifth embodiment. In this embodiment, the optical element 513 is mounted on a capacitor or thermistor 12. The capacitor is, for example, any one of capacitors 20, 21, and 22. In this case, for example, by making the dielectric substrate 6 have a thickness equivalent to that of the capacitor or thermistor 12, the optical element 513 can be brought closer to the semiconductor optical integrated device 10. Furthermore, by ensuring an area in which a conductive wire 32 can be bonded to the top electrode of the capacitor or thermistor 12, it becomes possible to directly supply power to the capacitor or thermistor 12 from the DC power supply lead pin 2 via the conductive wire 32.

[0052] This reduces the distance between the light emitting point and the optical element 13 compared to the first to third embodiments, shortening the optical path to the lens 17. This reduces vignetting at the lens 17 due to beam divergence. Furthermore, the miniaturization of the optical element 13 reduces material costs. Furthermore, since it is no longer necessary to install the optical element 13 on the upper substrate 5a, the degree of freedom in mounting can be improved.

[0053] Furthermore, for example, in a structure in which a mirror is mounted on a submount substrate, it is necessary to enlarge the submount substrate to ensure mounting space. This increases the material cost of the submount substrate. In contrast, in this embodiment, there is no need to enlarge the dielectric substrate 6, making it possible to reduce the size of the dielectric substrate 6 and the material cost of the dielectric substrate 6.

[0054] Sixth Embodiment Fig. 12 is a diagram illustrating a light receiving element 15 according to a sixth embodiment. The light receiving element 15 is mounted on the lead pin 2 for DC power supply. Specifically, the support block 14 on which the light receiving element 15 is mounted is mounted on the lead pin 2 for DC power supply. This eliminates the need for mounting space on the main surface of the stem 1 for the light receiving element 15. Therefore, the clearance on the main surface of the stem 1 can be increased.

[0055] An electrode pattern 14a is formed on the support block 14. A conductive thermosetting resin or solder is preferably used as a bonding material between the support block 14, the electrode pattern 14a, and the DC power supply lead pin 2. A conductive wire 33 is used to connect the electrode pattern 14a to the light receiving element 15 and to connect the electrode pattern 14a to the stem 1.

[0056] Seventh Embodiment. Figure 13 is a cross-sectional view showing the state in which an optical module 100 and a receptacle 102 according to a seventh embodiment are connected. Figure 14 is a perspective view of an optical transceiver 1000 according to the seventh embodiment. The optical transceiver 1000 of this embodiment may include any of the optical modules according to the first to sixth embodiments. The optical transceiver 1000 may include a fixing block 101 that is attached to the side of the stem 1 and covers the optical module 100. A receptacle 102 for fixing an optical fiber is attached to the fixing block 101. The fixing block 101 is joined to the side of the stem 1.

[0057] A substrate 903 carrying integrated circuits for driving the optical module 100 and the optical receiving module 106 is connected to the optical module 100 and the optical receiving module 106 via a flexible printed circuit board 105. In the optical transceiver 1000, the optical module 100, the optical receiving module 106, the flexible printed circuit board 105, the receptacle 102, and the substrate 903 are housed in a case 900 consisting of a lower housing 901 and an upper housing 902.

[0058] In order to increase the amount of heat transfer between the fixed block 101 and the lower housing 901, it is advisable to attach the lower heat dissipation block 103 to the fixed block 101, and then attach the lower heat dissipation block 103 to the lower housing 901. For bonding the fixed block 101 and the lower heat dissipation block 103, and for bonding the lower heat dissipation block 103 to the lower housing 901, a sheet-like insulator with high thermal conductivity or the like is used.

[0059] The lower heat dissipation block 103 preferably has a semicircular structure that allows the fixing block 101 to be fixed along the entire length of its side surface. This ensures a large bonding area between the fixing block 101 and the lower heat dissipation block 103. This improves the ability to radiate heat generated by the optical module 100 to the outside of the optical transceiver 1000, thereby reducing power consumption.

[0060] Furthermore, an upper heat dissipation block 104 may be attached to the fixed block 101. Like the lower heat dissipation block 103, the upper heat dissipation block 104 has a semicircular structure that allows the fixed block 101 to be fixed along the entire length of its side. Furthermore, the upper heat dissipation block 104 has fins on the side opposite the fixed block 101. By combining the lower heat dissipation block 103 and the upper heat dissipation block 104, heat can be efficiently dissipated from the entire periphery of the fixed block 101. This allows for further reductions in power consumption.

[0061] The technical features described in each embodiment may be used in appropriate combination.

[0062] 1 stem, 2 DC power supply lead pin, 3 RF power supply lead pin, 4 raised portion, 5 temperature control module, 5a upper substrate, 5b lower substrate, 6 dielectric substrate, 6a high frequency transmission line, 6b GND electrode pattern, 6c GND electrode pattern, 7 semiconductor laser, 8 optical modulator, 9 optical amplifier, 10 semiconductor optical integrated element, 11 matching resistor, 12 thermistor, 13 optical element, 14 support block, 14a electrode pattern, 15 light receiving element, 16 cap, 17 lens, 18 beam, 19 protective resistor, 20 capacitor, 21 capacitor, 22 capacitor, 30 conductive wire, 31 conductive wire, 32 conductive wire, 33 conductive wire, 40 waveguide, 41 substrate, 42 mirror, 43 light receiving portion, 100 optical module, 101 fixing block, 102 Receptacle, 103 Lower heat dissipation block, 104 Upper heat dissipation block, 105 Flexible printed circuit board, 106 Light receiving module, 200 Optical module, 300 Optical module, 400 Optical module, 410 Semiconductor optical integrated element, 513 Optical element, 900 Case, 901 Lower housing, 902 Upper housing, 903 Board, 1000 Optical transceiver

Claims

1. A stem having a main surface and a surface opposite to the main surface, a lead pin penetrating the stem from the main surface to the surface opposite to the main surface, a temperature control module mounted on the main surface of the stem, a dielectric substrate mounted on the surface opposite to the main surface of the temperature control module, and a semiconductor optical integrated element mounted on the surface opposite to the temperature control module of the dielectric substrate and having a semiconductor laser and an optical amplifier. A light module characterized by comprising.

2. The optical module according to claim 1, further comprising a first capacitor connecting the semiconductor laser and GND.

3. The optical module according to claim 1 or 2, further comprising a second capacitor connecting the optical amplifier and GND.

4. The optical module according to any one of claims 1 to 3, wherein the semiconductor optical integrated element has an optical modulator.

5. The optical module according to claim 4, further comprising a third capacitor connected in parallel with the optical modulator.

6. An impedance matching resistor connected in series with the third capacitor, and a series circuit formed by the third capacitor and the impedance matching resistor is connected in parallel with the optical modulator. The optical module according to claim 5, characterized in that.

7. The optical module according to claim 6, further comprising a protection resistor connected in parallel with the optical modulator, wherein the protection resistor has a larger resistance value than the impedance matching resistor.

8. A raised portion is formed on the main surface of the stem, and the optical module according to any one of claims 1 to 3, further comprising an RF power supply lead pin provided on the raised portion.

9. The semiconductor optical integrated element has an optical modulator, RF power supply metallization is formed on the dielectric substrate, one end of the RF power supply metallization is connected to the optical modulator by a wire, and the other end of the RF power supply metallization is connected to the RF power supply lead pin by a wire, solder or a conductive adhesive. The optical module according to claim 8, characterized in that.

10. GND metallization is formed on the side surface of the dielectric substrate, and the GND metallization is connected to the raised portion via a wire. The optical module according to claim 8 or 9, characterized in that.

11. The semiconductor optical integrated device includes an optical element that emits laser light parallel to the main surface of the stem and reflects the laser light perpendicular to the main surface of the stem. The optical module according to any one of claims 1 to 10, characterized in that.

12. The laser light is emitted obliquely with respect to the main axis of the semiconductor optical integrated device, and the optical element is oriented obliquely with respect to the main axis of the semiconductor optical integrated device. The optical module according to claim 11, characterized in that.

13. The optical module according to claim 11 or 12, characterized in that the optical element is mounted on a capacitor or a thermistor.

14. A light receiving element that receives the laser light is disposed on the side opposite to the semiconductor optical integrated device with respect to the optical element. The optical module according to any one of claims 11 to 13, characterized in that.

15. The optical module according to claim 14, characterized in that the light receiving element is mounted on the lead pin.

16. When viewed from a direction perpendicular to the main surface of the stem, the temperature control module is inclined with respect to the main axis of the semiconductor optical integrated device. The optical module according to any one of claims 1 to 15, characterized in that.

17. The semiconductor optical integrated device has an optical modulator, a first capacitor connecting the semiconductor laser and GND, a second capacitor connecting the optical amplifier and GND, and a third capacitor connected in parallel with the optical modulator. The optical module according to claim 1, characterized in that the first capacitor, the second capacitor, and the third capacitor are mounted side by side on the side opposite to the main surface of the stem of the temperature control module.

18. A mirror is formed on the front end surface of the semiconductor optical integrated device, and the mirror reflects the laser light of the semiconductor optical integrated device in a direction perpendicular to the main surface of the stem. The optical module according to any one of claims 1 to 10, characterized in that.

19. An optical transceiver comprising the optical module according to any one of claims 1 to 18.

20. A fixing block attached to the side surface of the stem and covering the optical module, and a receptacle attached to the fixing block for fixing an optical fiber. The optical transceiver according to claim 19, characterized in that.

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