JP7466773B1 - Optical Modules - Google Patents

Abstract

The optical module of the present disclosure comprises a stem (1), a base portion (20) arranged on the surface (1a) side of the stem and having a bottom portion (20a) facing the stem surface (1a) and a side portion (20b) along a direction perpendicular to the stem surface (1a), a submount (30) installed on the side portion (20b) of the base portion, a semiconductor optical integrated device (50) installed on the submount (30) and consisting of electrically independent portions, from the surface (1a) side of the stem, a semiconductor laser portion (50a), an optical modulator portion (50b), and an optical amplifier portion (50c), a capacitor (60) for the semiconductor laser portion connected to the semiconductor laser portion (50a), a capacitor (61) for the optical modulator portion connected to the optical modulator portion (50b), and a capacitor (62) for the optical amplifier portion connected to the optical amplifier portion (50c).

Description

The present disclosure relates to an optical module.

In recent years, the spread of various information terminals and the cloudification of information have led to a trend of increasing data traffic. To meet the growing demand for data traffic, efforts are underway to increase the transmission speed and capacity within optical fiber communication base stations.

As a light source for long-distance optical communications such as optical fiber communications, a semiconductor optical integrated device that monolithically integrates a semiconductor laser section, an optical modulator section, and an optical amplifier section is used (Patent Document 1). The optical modulator section is a type of external modulator, and since there is less degradation of the signal waveform compared to the direct modulation method that directly modulates the laser light intensity, high-speed and long-distance optical fiber transmission is possible. In addition, the optical amplifier section functions to amplify the modulated light.

JP 2022-099537 A

In the optical module described in Patent Document 1, the capacitor for the semiconductor laser section and the capacitor for the optical amplifier section are shared, and only one capacitor is arranged. In addition, the semiconductor optical integrated element is mounted in an oblique direction with respect to the direction perpendicular to the surface of the stem.

In the optical module described in Patent Document 1, the semiconductor laser section and the optical amplifier section are electrically connected in parallel, so the same current flows through the semiconductor laser section and the optical amplifier section, which creates a practical problem in that it is difficult to control the two sections independently.

This disclosure has been made to resolve the problems described above, and aims to provide an optical module that has high current controllability and can be miniaturized.

The optical module according to the present disclosure comprises:
A CAN package;
A stem which is one of the components constituting the CAN package;
a base portion disposed on a surface side of the stem, the base portion having a bottom surface facing the surface of the stem and a side surface extending in a direction perpendicular to the surface of the stem;
A submount disposed on a side surface of the base;
a semiconductor optical integrated device mounted on the submount and including, from a front surface side of the stem, a semiconductor laser section, an optical modulator section, and an optical amplifier section, each of which is electrically independent from the other;
a capacitor for a semiconductor laser portion electrically connected to the semiconductor laser portion of the semiconductor optical integrated device via a wire;
an optical modulator capacitor electrically connected to the optical modulator of the semiconductor optical integrated device via a wire;
an optical amplifier section capacitor electrically connected to the optical amplifier section of the semiconductor optical integrated device via a wire;
Equipped with
The submount is rectangular, the capacitor for the optical modulator section is disposed on the submount, and the capacitor for the semiconductor laser section and the capacitor for the optical amplifier section are disposed on another side portion of the base section along the side portion on which the submount is disposed .

According to the optical module of the present disclosure, current flows independently through capacitors that are electrically connected to the semiconductor laser section, optical modulator section, and optical amplifier section of the semiconductor optical integrated device mounted thereon, thereby achieving the effect of obtaining an optical module that has high current controllability and can be made compact.

1 is a schematic view of an optical module according to a first embodiment; 1 is a side view of an optical module according to a first embodiment; 1 is a side view of an optical module according to a first embodiment; 1 is a cross-sectional view of a semiconductor optical integrated device that is a part of an optical module according to a first embodiment. 1 is a schematic view of a CAN package which is a part of an optical module according to a first embodiment. FIG. 11 is a schematic view of an optical module according to a second embodiment. FIG. 11 is a side view of an optical module according to a second embodiment. FIG. 11 is a side view of an optical module according to a second embodiment. FIG. 11 is a schematic view of an optical module according to a third embodiment. FIG. 11 is a side view of an optical module according to a third embodiment. FIG. 11 is a side view of an optical module according to a third embodiment. FIG. 13 is a schematic view of an optical module according to a fourth embodiment. FIG. 13 is a side view of an optical module according to a fourth embodiment. FIG. 13 is a side view of an optical module according to a fourth embodiment. FIG. 13 is a schematic view of an optical module according to a fifth embodiment. FIG. 13 is a side view of an optical module according to a fifth embodiment. FIG. 13 is a side view of an optical module according to a fifth embodiment.

Embodiment 1.
Fig. 1 is a schematic view of an optical module 100 according to the first embodiment. Fig. 2 and Fig. 3 are side views of the optical module 100 according to the first embodiment.

Stem 1 is generally circular and plate-like. Stem 1 is made of a material with high thermal conductivity, such as copper (Cu), with its surface plated with Au. Stem 1 is provided with a number of lead pins 2a to 2f that penetrate the stem 1.

Glass 3 is generally used to secure lead pins 2a to 2f to stem 1. If impedance mismatch occurs, multiple reflections of the signal will cause degradation of frequency response characteristics, making high-speed modulation difficult. Therefore, glass 3 is made of a material with a low dielectric constant.

A temperature control module 10 is disposed on the surface 1a of the stem. The surface 1a of the stem refers to the flat surface of the stem 1, which has a circular plate shape, from which the lead pins 2a to 2f protrude. The temperature control module 10 is configured to sandwich a plurality of thermoelectric elements made of a material such as bismuth telluride (BiTe) between a lower substrate and an upper substrate made of a material such as aluminum nitride (AlN). The lower substrate of the temperature control module 10 has a protruding portion that protrudes in a direction parallel to the surface 1a of the stem more than the upper substrate, and electrode patterns 10a and 10b for supplying power to the thermoelectric elements (not shown) are provided on the protruding portion. The temperature control module 10 is provided to control the temperature of the semiconductor optical integrated element 50, which will be described later. In the optical module 100 according to the first embodiment, the temperature control module 10 may be omitted.

A pedestal 20 is installed on the surface of the temperature control module 10. The bottom surface 20a of the pedestal faces the surface 1a of the stem via the temperature control module 10. The bottom surface 20a of the pedestal and the surface of the temperature control module 10 are joined by a joining material such as SnAgCu solder or AuSn solder.

The base 20 has side portions 20b and 20c. The base 20 is made of a block of metal material, for example, Cu or other material with high thermal conductivity, with Au plating applied to the surface. The base 20, which is a separate part from the stem 1, may be mounted on the stem 1, or the stem 1 and the base 20 may be molded integrally.

The submount 30 is mounted on the side portion 20b of the base. The submount 30 is, for example, a rectangular parallelepiped plate-like member made of a dielectric material. The submount 30 is made of a ceramic material such as AlN, and has electrical insulation and heat transfer functions. The submount 30 has a main surface and a back surface opposite each other, and four side surfaces. The back surface of the submount 30 is mounted on the side portion 20b of the base. A metal pattern is patterned on the main surface of the submount 30.

A semiconductor optical integrated element 50 is installed on the main surface side of the submount 30. As shown in the cross-sectional view of FIG. 4, the semiconductor optical integrated element 50 is composed of a semiconductor laser section 50a, an optical modulator section 50b, and an optical amplifier section 50c. The sections are installed from the bottom surface section 20a side of the base section so that the semiconductor laser section 50a, the optical modulator section 50b, and the optical amplifier section 50c are arranged in the order of the semiconductor laser section 50a, the optical modulator section 50b, and the optical amplifier section 50c. The semiconductor laser section 50a, the optical modulator section 50b, and the optical amplifier section 50c are each electrically independent. The semiconductor optical integrated element 50 is also mounted in an oblique direction with respect to the direction perpendicular to the surface 1a of the stem.

The semiconductor laser section 50a of the semiconductor optical integrated device 50 is, for example, a distributed feedback semiconductor laser (DFB laser). The optical modulator section 50b of the semiconductor optical integrated device 50 is, for example, an electroabsorption optical modulator using an InGaAsP-based quantum well absorption layer. The optical amplifier section 50c of the semiconductor optical integrated device 50 is, for example, an InGaAsP-based optical amplifier.

Because the oscillation wavelength of the semiconductor optical integrated element 50 varies with changes in temperature, it is necessary to keep the temperature of the semiconductor optical integrated element 50 as constant as possible. When the temperature of the semiconductor optical integrated element 50 rises, the temperature control module 10 cools it, while when the temperature of the semiconductor optical integrated element 50 drops, the temperature control module 10 generates heat to keep the temperature of the semiconductor optical integrated element 50 constant.

Heat generated by the operation of the semiconductor optical integrated element 50 is transferred to the upper substrate of the temperature control module 10 via the submount 30. The temperature control module 10 absorbs the heat generated by the semiconductor optical integrated element 50. The heat absorbed by the temperature control module 10 is dissipated from the lower substrate of the temperature control module 10 through the stem 1 to a heat sink (not shown) on the back side of the stem 1.

In the semiconductor optical integrated element 50, a capacitor 60 for the semiconductor laser section, a capacitor 61 for the optical modulator section, and a capacitor 62 for the optical amplifier section are arranged in that order on the side surface 20b of the base from the bottom surface 20a side of the base along the side perpendicular to the surface 1a of the stem of the submount 30 mounted on the side surface 20b of the base.

The thermistor 55 is installed on the side surface 20c of the pedestal opposite to the side surface 20b of the pedestal on which the submount 30 is installed. The thermistor 55 is a type of temperature sensor, and indirectly measures the temperature of the semiconductor optical integrated element 50. The temperature measured by the thermistor 55 is fed back to the temperature control module 10. The temperature control module 10 controls the temperature of the semiconductor optical integrated element 50 based on the temperature measured by the thermistor 55, thereby stabilizing the temperature of the semiconductor optical integrated element 50. As a result, a constant oscillation wavelength is stably obtained.

The lead pin 2a is electrically connected to the thermistor 55 via a conductive wire W1. The lead pin 2b is electrically connected to the semiconductor laser capacitor 60 via a conductive wire W2. The lead pin 2c is electrically connected to the optical amplifier capacitor 62 via a conductive wire W3. The lead pin 2d is electrically connected to the electrode pattern 10a of the temperature control module 10 via a conductive wire W4. The lead pin 2e is electrically connected to the electrode pattern 10b of the temperature control module 10 via a conductive wire W5. The lead pin 2f is once electrically connected to the electrode pattern 80a of the auxiliary substrate 80 fixed to the side of the auxiliary block 79, and is electrically connected to the optical modulator section 50b of the semiconductor optical integrated device 50 via the electrode pattern 30e on the submount 30. In addition, since the arrangement of the conductive wires and electrode patterns in FIG. 2 and FIG. 3 is the same as that in FIG. 1, the symbols of the conductive wires and electrode patterns are omitted to avoid complication.

The capacitor 60 for the semiconductor laser section is first electrically connected to the electrode pattern 30a on the submount 30 via a conductive wire W6, and is further electrically connected to the semiconductor laser section 50a of the semiconductor optical integrated device 50 via a conductive wire W7.

The capacitor 61 for the optical modulator section is first electrically connected to the electrode pattern 30b on the submount 30 via a conductive wire W8, and is further electrically connected to the optical modulator section 50b of the semiconductor optical integrated device 50 via a conductive wire W9.

The capacitor 62 for the optical amplifier section is first electrically connected to the electrode pattern 30c on the submount 30 via a conductive wire W10, and is further electrically connected to the optical amplifier section 50c of the semiconductor optical integrated device 50 via a conductive wire W11.

Electrode pattern 80a of the auxiliary substrate 80 is electrically connected to electrode pattern 30e on the submount 30 via conductive wire W23. Electrode pattern 80b of the auxiliary substrate 80 is electrically connected to electrode pattern 30d on the submount 30 via conductive wire W21. Electrode pattern 80c of the auxiliary substrate 80 is electrically connected to electrode pattern 30f on the submount 30 via conductive wire W22.

The optical module 100 according to the first embodiment uses a CAN package 90 as shown in Fig. 5 as a package. That is, the temperature control module 10, the base 20, the submount 30, the auxiliary block 79, the auxiliary substrate 80, etc., which are provided on the front surface 1a side of the stem, are housed inside the CAN case 91. Note that the lead pins 2 protrude from the rear surface side of the stem 1.

Since the optical module 100 according to the first embodiment employs the above-mentioned configuration, the semiconductor laser section 50a, the optical modulator section 50b, and the optical amplifier section 50c can be individually current-controlled via the capacitor 60 for the semiconductor laser section, the capacitor 61 for the optical modulator section, and the capacitor 62 for the optical amplifier section, respectively, and therefore the controllability of the drive current for the semiconductor optical integrated device 50 is high. In other words, the effect of improving the current controllability of the optical module 100 according to the first embodiment is achieved.

In addition, a capacitor 60 for the semiconductor laser section, a capacitor 61 for the optical modulator section, and a capacitor 62 for the optical amplifier section are arranged in order from the bottom surface 20a side of the pedestal along the side surface perpendicular to the surface 1a of the stem of the submount 30 mounted on the side surface 20b of the pedestal, thereby achieving the effect of making it possible to miniaturize the optical module.

<Effects of First Embodiment>
As described above, according to the optical module of the first embodiment, current flows independently through capacitors that are electrically connected to the semiconductor laser section, the optical modulator section, and the optical amplifier section of the mounted semiconductor optical integrated device, respectively. This has the effect of providing an optical module that has high controllability of the current, and that can be made compact because the capacitors are arranged in sequence on the side section of the base.

Embodiment 2.
Fig. 6 is a schematic view of an optical module 110 according to the second embodiment. Figs. 7 and 8 are side views of the optical module 110 according to the second embodiment. The following description focuses on the differences from the optical module 100 according to the first embodiment. In Figs. 6 to 8, the arrangement of the conductive wires and electrode patterns is the same as in the first embodiment, and therefore the reference numerals are omitted to avoid complication.

In the optical module 110 according to the second embodiment, as shown in Figures 6 and 8, the capacitor 61 for the optical modulator section is disposed on the submount 30. The capacitor 60 for the semiconductor laser section and the capacitor 62 for the optical amplifier section are disposed on the surface of the upper substrate of the temperature control module 10.

By arranging the capacitors as described above, it is possible to reduce the width along the side portion 20b of the base compared to the structure of the optical module 100 according to embodiment 1. In other words, the CAN package 90 that houses the stem 1, temperature control module 10, base portion 20, submount 30, auxiliary block 79, auxiliary substrate 80, etc. of the optical module 110 can be made smaller.

In addition, the temperature control module 10 may be configured to have the same area as the bottom surface 20a of the base, and the capacitor 60 for the semiconductor laser section and the capacitor 62 for the optical amplifier section may be arranged directly on the surface 1a of the stem.

<Effects of the Second Embodiment>
As described above, according to the optical module of the second embodiment, current flows independently through capacitors that are electrically connected to the semiconductor laser section, optical modulator section, and optical amplifier section of the mounted semiconductor optical integrated device, thereby achieving the effect of high current controllability, and since the capacitor for the optical modulator section is disposed on the submount, and the capacitor for the semiconductor laser section and the capacitor for the optical amplifier section are disposed on the temperature control module, an optical module that can be further miniaturized is obtained.

Embodiment 3.
Fig. 9 is a schematic view of an optical module 120 according to the third embodiment. Figs. 10 and 11 are side views of the optical module 120 according to the third embodiment. The following description will focus on the differences from the optical module 100 according to the first embodiment. In Figs. 9 to 11, the arrangement of the conductive wires and electrode patterns is the same as in the first embodiment, and therefore, in order to avoid complication, reference numerals other than those for parts necessary for the description are omitted.

In the optical module 120 according to the third embodiment, the base 20 has a rectangular parallelepiped shape as shown in Figs. 9 to 11. In addition, parts of the electrode patterns 30a and 30c on the submount 30 are also provided on the side surfaces of the submount 30.

In the optical module 120 according to the third embodiment, as shown in Figures 9 to 11, the capacitor 61 for the optical modulator section is disposed on the submount 30. The capacitor 60 for the semiconductor laser section and the capacitor 62 for the optical amplifier section are disposed on the side surface 20d of the pedestal section. The side surface 20d of the pedestal section refers to the side surface that is closer to the capacitor 61 for the optical modulator section among the two side surfaces perpendicular to the side surface 20b and the side surface 20c of the pedestal section that face each other.

In other words, the capacitor 61 for the optical modulator section is placed on the submount 30, and the capacitor 60 for the semiconductor laser section and the capacitor 62 for the optical amplifier section are placed on the other side portion 20d of the base along the side portion 20b of the base on which the submount 30 is placed.

The reason why a part of the electrode pattern 30a and the electrode pattern 30c are also provided on the side portion of the submount 30 is that such an arrangement is necessary in order to connect the semiconductor laser section capacitor 60 installed on the side portion 20d of the pedestal to the electrode pattern 30a, and the optical amplifier section capacitor 62 to the electrode pattern 30c with conductive wires. In other words, it is technically difficult to directly connect the capacitors installed on the side portion 20d of the pedestal to the semiconductor optical integrated element 50 installed on the side portion 20b of the pedestal with conductive wires.

By arranging the capacitors as described above, it is possible to reduce the width along the side portion 20b of the base compared to the structure of the optical module 100 according to embodiment 1. In other words, the CAN package 90 that houses the stem 1, temperature control module 10, base portion 20, submount 30, auxiliary block 79, auxiliary substrate 80, etc. of the optical module 120 can be made smaller.

In addition, instead of providing a portion of the electrode pattern 30a and a portion of the electrode pattern 30c on the submount 30 on the side portion of the submount 30, small conductive blocks may be bonded onto the electrode pattern 30a and the electrode pattern 30c of the submount 30, respectively, and the conductive blocks may be connected to the capacitor 60 for the semiconductor laser section and the capacitor 62 for the optical amplifier section by conductive wires.

<Effects of Third Embodiment>
As described above, according to the optical module of the third embodiment, current flows independently through capacitors electrically connected to the semiconductor laser section, optical modulator section, and optical amplifier section of the mounted semiconductor optical integrated device, thereby providing the effect of high current controllability, and since the capacitor for the optical modulator section is disposed on the submount, and the capacitor for the semiconductor laser section and the capacitor for the optical amplifier section are disposed on the other side sections of the base, it is possible to obtain an optical module that can be further miniaturized.

Embodiment 4.
Fig. 12 is a schematic view of an optical module 130 according to the fourth embodiment. Figs. 13 and 14 are side views of the optical module 130 according to the fourth embodiment. The following description focuses on the differences from the optical module 100 according to the first embodiment. In Figs. 12 to 14, the arrangement of the conductive wires and electrode patterns is the same as in the first embodiment, and therefore the reference numerals are omitted to avoid complication.

In the optical module 130 according to the fourth embodiment, as shown in Figures 12 to 14, the arrangement of each capacitor is the same as that of the optical module 100 according to the first embodiment. The optical module 130 according to the fourth embodiment is characterized in that the cross-sectional shape of the other side portion 20d of the base along the side portion 20b of the base on which the submount 30 is installed is L-shaped.

By making the cross-sectional shape of the side surface 20d of the pedestal part L-shaped, it is possible to reduce the height of the pedestal part 20 from the surface 1a of the stem compared to the height of the pedestal part of the optical module 100 according to embodiment 1. As a result, the CAN package 90 that houses the stem 1, temperature control module 10, pedestal part 20, submount 30, auxiliary block 79, auxiliary substrate 80, etc. of the optical module 130 can be made smaller.

<Effects of Fourth Embodiment>
As described above, according to the optical module of the fourth embodiment, current flows independently through capacitors that are electrically connected to the semiconductor laser portion, the optical modulator portion, and the optical amplifier portion of the mounted semiconductor optical integrated device, respectively, thereby providing the effect of high current controllability, and since the cross-sectional shape of the side portion of the base is L-shaped, it is possible to obtain an optical module that can be further miniaturized.

Embodiment 5.
Fig. 15 is a schematic view of an optical module 140 according to embodiment 4. Figs. 16 and 17 are side views of the optical module 140 according to embodiment 4. In Figs. 15 to 17, the arrangement of the conductive wires and electrode patterns is similar to that of embodiment 1, and therefore the reference numerals are omitted to avoid complication.

As shown in Figures 15 and 17, the optical module 140 according to the fifth embodiment does not have a base 20, and instead the submount 30 also serves as the base. The arrangement of the capacitors is the same as that of the optical module 100 according to the first embodiment.

In the optical module 140 according to the fifth embodiment, since there is no need to provide a pedestal portion 20 as in the first to fourth embodiments, the number of parts in the optical module can be reduced. In addition, since the height of the submount 30 is lower than the height of the pedestal portion 20 in the first to fourth embodiments, the CAN package 90 that houses the stem 1, temperature control module 10, submount 30, auxiliary block 79, auxiliary substrate 80, etc. of the optical module 140 can be made smaller.

<Effects of the Fifth Embodiment>
As described above, according to the optical module of the fifth embodiment, current flows independently through capacitors that are electrically connected to the semiconductor laser portion, the optical modulator portion, and the optical amplifier portion of the mounted semiconductor optical integrated device, respectively, thereby achieving the effect of high current controllability, and since the base portion can be omitted, the number of components of the optical module can be reduced, thereby achieving the effect of obtaining an optical module that can be made smaller and less expensive.

While the present disclosure describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments are not limited to application to a particular embodiment, but may be applied to the embodiments alone or in various combinations.

Therefore, countless variations not illustrated are contemplated within the scope of the technology disclosed in this specification. For example, this includes modifying, adding, or omitting at least one component, or extracting at least one component and combining it with a component of another embodiment.

1 stem, 1a surface of stem, 2, 2a, 2b, 2c, 2d, 2e, 2f lead pin, 3 glass, 10 temperature control module, 10a, 10b, 30a, 30b, 30c, 30d, 30e, 30f, 80a, 80b, 80c electrode pattern, 20 pedestal portion, 20a bottom surface portion of pedestal portion, 20b, 20c, 20d side surface portion of pedestal portion, 30 submount, 50 semiconductor optical integrated element, 50a semiconductor laser portion, 50b optical modulator portion, 50c optical amplifier portion, 55 thermistor, 60 capacitor for semiconductor laser portion, 61 capacitor for optical modulator portion, 62 capacitor for optical amplifier portion, 79 auxiliary block, 80 auxiliary substrate, 90 CAN package, 91 CAN case, 100, 110, 120, 130, 140 Optical module, W1, W2, W3, W4, W5, W6, W7, W8, W9, W10, W11, W21, W22, W23 Conductive wire

Claims (5)

A CAN package;
A stem which is one of the components constituting the CAN package;
a base portion disposed on a surface side of the stem, the base portion having a bottom surface facing the surface of the stem and a side surface extending in a direction perpendicular to the surface of the stem;
A submount disposed on a side surface of the base;
a semiconductor optical integrated device mounted on the submount and including, from a front surface side of the stem, a semiconductor laser section, an optical modulator section, and an optical amplifier section, each of which is electrically independent from the other;
a capacitor for a semiconductor laser portion electrically connected to the semiconductor laser portion of the semiconductor optical integrated device via a wire;
an optical modulator capacitor electrically connected to the optical modulator of the semiconductor optical integrated device via a wire;
an optical amplifier section capacitor electrically connected to the optical amplifier section of the semiconductor optical integrated device via a wire;
Equipped with
An optical module characterized in that the submount is rectangular, the capacitor for the optical modulator section is placed on the submount, and the capacitor for the semiconductor laser section and the capacitor for the optical amplifier section are placed on other side portions of the base section along the side portion on which the submount is placed. 2. The optical module according to claim 1, further comprising a temperature control module disposed between the stem and the base. 2. The optical module according to claim 1 , wherein the semiconductor optical integrated device is disposed at an angle to a direction perpendicular to a surface of the stem. 2. The optical module according to claim 1 , wherein the semiconductor laser section and the capacitor for the semiconductor laser section are electrically connected by the wire via an electrode pattern extending from the front surface of the submount to a side surface. 2. The optical module according to claim 1 , wherein the optical amplifier section and the capacitor for the optical amplifier section are electrically connected by the wire via an electrode pattern extending from the front surface of the submount to a side surface.

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