WO2022007428A1

WO2022007428A1 - Optical module

Info

Publication number: WO2022007428A1
Application number: PCT/CN2021/080817
Authority: WO
Inventors: 尹延龙; 陈思涛; 隋少帅; 赵其圣
Original assignee: 青岛海信宽带多媒体技术有限公司
Priority date: 2020-07-07
Filing date: 2021-03-15
Publication date: 2022-01-13
Also published as: CN113917624A; CN113917624B

Abstract

An optical module (200), comprising a circuit board (105), a light source (500), and a photonic integrated chip (400). A power divider on the photonic integrated chip (400) comprises a substrate (403) and a dual-core waveguide. The dual-core waveguide comprises an input section waveguide and a power division section waveguide which are integrally connected to each other. The distance between first and second waveguides of the input section waveguide is gradually decreased in the light propagation direction to evolve the first and second waveguides from a single mode into a dual-core waveguide mode. The widths of the first and second waveguides are different, and gradually narrow in the light propagation direction until the widths of the first and second waveguides are identical, so that the power of light on the first and second waveguides is identical. The distance between first and second waveguides of the power division section waveguide is gradually increased in the light propagation direction to divide the input light into two lights having the same power, and lights respectively output by the first and second waveguides have specific phases. By optimizing the design of the width and length of the dual-core waveguide, the optical signal splitting in a wide spectral band is realized, and output optical signals have a specific phase relation.

Description

an optical module

This disclosure requires that it be submitted to the China Patent Office on July 7, 2020, with the application number of 202021324138.4 and the patent name of "An Optical Module", and submitted to the China Patent Office on September 25, 2020, with the application number of 202011026255.7 and the patent name of Priority for "an optical module," which is incorporated by reference in this disclosure in its entirety.

technical field

The present disclosure relates to the technical field of optical communication, and in particular, to an optical module.

Background technique

Optical communication technology will be used in new business and application modes such as cloud computing, mobile Internet, and video. In optical communication, the optical module is a tool for realizing the mutual conversion of photoelectric signals, and it is one of the key components in optical communication equipment. Among them, because the photonic integrated chip has the advantages of small size, high integration density and low cost, the use of the photonic integrated chip to realize the electro-optical-photoelectric conversion function has become a mainstream solution adopted by high-speed optical modules.

For high-speed optical modules, multiplexing has become a mainstream solution, such as 400G DR4 optical modules, 400G LR8 optical module products, etc. It is necessary to divide the optical signal output by one laser into 2 or 4 channels, etc., and then undergo high-speed modulation. The power divider plays an important role in high-speed optical module products.

SUMMARY OF THE INVENTION

An embodiment of the present disclosure discloses an optical module, comprising: a circuit board; a light source, electrically connected to the circuit board, for emitting light without a signal; a photonic integrated chip, electrically connected to the circuit board, the photonic The input optical port of the integrated chip is provided with a power splitter, which is used to divide the light that does not carry a signal into multiple paths of light; the photonic integrated chip modulates the multiple paths of light into signal light and passes the light of the photonic integrated chip. The output optical port outputs the signal light; the power splitter includes: a substrate; a dual-core waveguide is arranged on the substrate and includes an input section waveguide and a power section waveguide that are integrally connected, and the input section waveguide is The distance between the first waveguide and the second waveguide is gradually reduced in the light propagation direction, so as to evolve the first waveguide and the first waveguide from a single mode into a dual-core waveguide mode; the first waveguide and the The widths of the second waveguides are different, and the widths of the two are gradually narrowed in the light propagation direction until the widths of the first waveguide and the second waveguide are the same, so that the first waveguide or the second waveguide has the same width. The power of the light without signal input by the waveguide on the first waveguide and the second waveguide is the same; the distance between the first waveguide and the second waveguide of the power segmented waveguide is in the light propagation direction gradually increase, so that the input light without signal is divided into two paths of light with the same power, and the lights respectively output from the first waveguide and the second waveguide have a specific phase.

Description of drawings

In order to illustrate the technical solutions of the present disclosure more clearly, the accompanying drawings that need to be used in the embodiments will be briefly introduced below. Other drawings can also be obtained from these drawings.

Fig. 1 is a schematic diagram of the connection relationship of optical communication terminals;

FIG. 2 is a schematic structural diagram of an optical network terminal;

FIG. 3 is a schematic structural diagram of an optical module according to an embodiment of the present disclosure;

FIG. 4 is a schematic diagram of an exploded structure of an optical module according to an embodiment of the present disclosure;

5 is a schematic structural diagram of a circuit board in an optical module according to an embodiment of the present disclosure;

6 is a schematic diagram of a power divider in an optical module provided by an embodiment of the present disclosure;

7 is a schematic structural diagram of a power divider in an optical module provided by an embodiment of the present disclosure;

FIG. 8 provides a schematic diagram of a partition of a power divider in an optical module according to an embodiment of the present disclosure;

Fig. 9 is the cross-sectional schematic diagram of A-A' direction in Fig. 8;

Figure 10 is a schematic cross-sectional view in the direction B-B' in Figure 8;

Figure 11 is a schematic cross-sectional view in the direction of C-C' in Figure 8;

Fig. 12 is the cross-sectional schematic diagram of D-D' direction in Fig. 8;

Figure 13 is a schematic cross-sectional view in the direction of E-E' in Figure 8;

14 is a schematic diagram of an optical transmission path in a power splitter provided by an embodiment of the present disclosure;

FIG. 15 is a schematic diagram of another optical transmission path in the power divider provided by the embodiment of the present disclosure.

detailed description

The technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, but not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present disclosure.

One of the core links of optical fiber communication is the mutual conversion of optical and electrical signals. Optical fiber communication uses information-carrying optical signals to transmit in information transmission equipment such as optical fibers/optical waveguides. The passive transmission characteristics of light in optical fibers/optical waveguides can realize low-cost, low-loss information transmission; while computers and other information processing equipment Electrical signals are used. In order to establish an information connection between information transmission equipment such as optical fibers/optical waveguides and information processing equipment such as computers, it is necessary to realize the mutual conversion of electrical signals and optical signals.

The optical module realizes the mutual conversion function of the above-mentioned optical and electrical signals in the technical field of optical fiber communication, and the mutual conversion of the optical signal and the electrical signal is the core function of the optical module. The optical module realizes the electrical connection with the external host computer through the gold finger on its internal circuit board. The main electrical connections include power supply, I2C signal, data information and grounding, etc. The electrical connection realized by the gold finger has become the optical module. The mainstream connection method of the industry, based on this, the definition of pins on the gold finger has formed a variety of industry protocols/norms.

FIG. 1 is a schematic diagram of a connection relationship of an optical communication terminal. As shown in FIG. 1 , the connection of the optical communication terminal mainly includes the interconnection between the optical network terminal 100 , the optical module 200 , the optical fiber 101 and the network cable 103 .

One end of the optical fiber 101 is connected to the remote server, and one end of the network cable 103 is connected to the local information processing device. The connection between the local information processing device and the remote server is completed by the connection between the optical fiber 101 and the network cable 103; and the connection between the optical fiber 101 and the network cable 103 is completed by The optical network terminal 100 with the optical module 200 is completed.

The optical port of the optical module 200 is externally connected to the optical fiber 101, and a two-way optical signal connection is established with the optical fiber 101; the electrical port of the optical module 200 is externally connected to the optical network terminal 100, and a two-way electrical signal connection is established with the optical network terminal 100; The optical module internally realizes the mutual conversion of optical signals and electrical signals, so as to establish an information connection between the optical fiber and the optical network terminal. In an embodiment of the present disclosure, an optical signal from an optical fiber is converted into an electrical signal by an optical module and then input to the optical network terminal 100 , and an electrical signal from the optical network terminal 100 is converted into an optical signal by an optical module and input into the optical fiber.

The optical network terminal has an optical module interface 102, which is used to access the optical module 200 and establish a two-way electrical signal connection with the optical module 200; Signal connection; the connection between the optical module 200 and the network cable 103 is established through the optical network terminal 100 . In an embodiment of the present disclosure, the optical network terminal transmits the signal from the optical module to the network cable, and transmits the signal from the network cable to the optical module, and the optical network terminal serves as the upper computer of the optical module to monitor the operation of the optical module.

So far, the remote server has established a two-way signal transmission channel with the local information processing equipment through optical fibers, optical modules, optical network terminals and network cables.

Common information processing equipment includes routers, switches, electronic computers, etc.; the optical network terminal is the host computer of the optical module, providing data signals to the optical module and receiving data signals from the optical module. Common optical module host computers and optical lines terminal etc.

FIG. 2 is a schematic structural diagram of an optical network terminal. As shown in FIG. 2 , the optical network terminal 100 has a circuit board 105, and a cage 106 is provided on the surface of the circuit board 105; an electrical connector is provided inside the cage 106 for connecting to an optical module electrical port such as a golden finger; The cage 106 is provided with a radiator 107 , and the radiator 107 has raised portions such as fins that increase the heat dissipation area.

The optical module 200 is inserted into the optical network terminal 100 , specifically, the electrical port of the optical module is inserted into the electrical connector inside the cage 106 , and the optical port of the optical module is connected to the optical fiber 101 .

The cage 106 is located on the circuit board, and the electrical connectors on the circuit board are wrapped in the cage, so that the interior of the cage is provided with electrical connectors; the optical module is inserted into the cage, the optical module is fixed by the cage, and the heat generated by the optical module is conducted to the cage. 106 and then diffuse through a heat sink 107 on the cage.

FIG. 3 is a schematic structural diagram of an optical module according to an embodiment of the present disclosure, and FIG. 4 is a schematic structural diagram of an exploded optical module according to an embodiment of the present disclosure. As shown in FIGS. 3 and 4 , the optical module 200 provided by the embodiment of the present disclosure includes an upper casing 201 , a lower casing 202 , an unlocking part 203 , a circuit board 300 , a photonic integrated chip 400 , a light source 500 and an optical fiber socket 600 .

The upper casing 201 is covered with the lower casing 202 to form a wrapping cavity with two openings; the outer contour of the wrapping cavity generally presents a square body. In an embodiment of the present disclosure, the lower case 202 includes a main board and two side plates located on both sides of the main board and perpendicular to the main board; the upper case includes a cover plate, and the cover plates are closed on the two sides of the upper case to form a wrapping cavity; the upper shell can also include two side walls located on both sides of the cover plate and vertically arranged with the cover plate, and the two side walls are combined with the two side plates to realize the upper shell 201 The cover is closed on the lower case 202 .

Specifically, the two openings may be two openings (204, 205) at the same end of the optical module, or two openings at different ends of the optical module; one of the openings is the electrical port 204, and the gold fingers of the circuit board extend from the electrical port 204. The other opening is the optical port 205, which is used for external optical fiber access to connect the photonic integrated chip 400 inside the optical module; the circuit board 300, the photonic integrated chip 400, the light source 500 and other optoelectronic devices located in the package cavity.

The combination of the upper casing and the lower casing is adopted, which facilitates the installation of devices such as the circuit board 300 and the photonic integrated chip 400 into the casing, and the upper casing and the lower casing form the outermost packaging protection casing of the module; The upper casing and the lower casing are generally made of metal materials, which are used to achieve electromagnetic shielding and heat dissipation. Generally, the casing of the optical module is not made into an integral part, so that when assembling circuit boards and other devices, positioning parts, heat dissipation and electromagnetic shielding parts It cannot be installed and is not conducive to production automation.

The unlocking part 203 is located on the outer wall of the enclosing cavity/lower casing 202, and is used to realize the fixed connection between the optical module and the upper computer, or to release the fixed connection between the optical module and the upper computer.

The unlocking part 203 has an engaging part matched with the cage of the upper computer; pulling the end of the unlocking part can make the unlocking part move relatively on the surface of the outer wall; the optical module is inserted into the cage of the upper computer, and the optical module is moved by the engaging part of the unlocking part. It is fixed in the cage of the upper computer; by pulling the unlocking part, the engaging part of the unlocking part moves with it, thereby changing the connection relationship between the engaging part and the upper computer, so as to release the engaging relationship between the optical module and the upper computer, so that the The optical module is pulled out from the cage of the host computer.

The circuit board 300 is provided with circuit traces, electronic components (such as capacitors, resistors, triodes, MOS tubes) and chips (such as MCU, laser driver chip, amplitude limiting amplifier chip, clock data recovery CDR, power management chip, data processing chip) DSP), etc.

The circuit board 300 connects the electrical components in the optical module together according to the circuit design through circuit wiring, so as to realize electrical functions such as power supply, electrical signal transmission, and grounding.

The circuit board is generally a rigid circuit board. Due to its relatively hard material, the rigid circuit board can also realize the bearing function. For example, the rigid circuit board can carry the chip smoothly; when the optical transceiver components are located on the circuit board, the rigid circuit board can also provide Stable bearing; the rigid circuit board can also be inserted into the electrical connector in the upper computer cage. In an embodiment of the present disclosure, metal pins/gold fingers are formed on one end surface of the rigid circuit board for connecting with the electrical connector. Connector connections; these are inconvenient to implement with flexible circuit boards.

Flexible circuit boards are also used in some optical modules as a supplement to rigid circuit boards; flexible circuit boards are generally used in conjunction with rigid circuit boards. For example, flexible circuit boards can be used to connect the rigid circuit boards and optical transceiver components.

FIG. 5 is a schematic structural diagram of a circuit board in an optical module according to an embodiment of the present disclosure. As shown in FIG. 5 , the photonic integrated chip 400 is disposed on the circuit board 300 and is electrically connected to the circuit board 300 , which may be connected by wire bonding; the periphery of the photonic integrated chip 400 and the circuit board 300 are connected by a plurality of conductive wires , so the photonic integrated chip 400 is generally disposed on the surface of the circuit board 300 .

In this example, the light source 500 can be a laser box, the photonic integrated chip 400 and the laser box are optically connected through the first optical fiber ribbon 401, and the photonic integrated chip 400 receives the light from the laser box through the first optical fiber ribbon 401, and then aligns the light The modulation is performed, specifically, the signal is loaded onto the light; the photonic integrated chip 400 receives the light from the optical fiber socket 600, and then converts the optical signal into an electrical signal.

The optical connection between the photonic integrated chip 400 and the optical fiber socket 600 is realized through the second optical fiber ribbon 402, and the optical fiber socket 600 realizes the optical connection with the external optical fiber of the optical module. The light modulated by the photonic integrated chip 400 is transmitted to the optical fiber socket 600 through the second optical fiber ribbon 402, and is transmitted to the external optical fiber through the optical fiber socket 600; the light from the external optical fiber is transmitted to the second optical fiber ribbon 402 through the optical fiber socket 600, and is transmitted through the second optical fiber. The tape 402 is transmitted to the photonic integrated chip 400, so that the photonic integrated chip 400 outputs the light carrying data to the external optical fiber of the optical module, or receives the light carrying data from the external optical fiber of the optical module.

In this example, the photonic integrated chip 400 is provided with an input optical port, an output optical port, a monitoring optical port, a high-speed electrical signal interface, a DC bias signal interface, etc., wherein the input optical port includes a first input optical port and a second input optical port , the first input optical port is used to couple the light output from the laser box into the photonic integrated chip 400, the second input optical port is used to couple the light received by the external fiber of the optical module and carry the data into the photonic integrated chip 400, and the output optical port It is used to couple the modulated signal out of the photonic integrated chip 400 .

Photonic integrated chips can integrate optical devices such as filters, beam splitters, polarization controllers, and detectors into the chip, without using space optics for optical devices such as TOSA, filters, beam splitters, polarizers, focusing lenses, and detectors. The system is packaged, which reduces the number of optical devices used, makes the structure of the chip system simpler, and greatly reduces the volume of the optical module.

The base material of the photonic integrated chip can be indium phosphide, gallium arsenide, lithium niobate, silicon, silicon dioxide, etc., wherein, silicon/silicon dioxide is the basic material used in the production of electronic integrated chips. An integrated chip (silicon photonics chip) is taken as an example for description.

The following is an example of dividing the optical signal output by one channel of the laser into multiple channels of optical signals and modulating them separately, in conjunction with a power divider provided in the first optical input port.

FIG. 6 is a schematic diagram of a power divider in an optical module provided by an embodiment of the present disclosure. As shown in FIG. 6 , the power divider is a 4-port device.

Ports

1 and 2 are input ports,

ports

3 and 4 are output ports, and

ports

1 and 2 are respectively connected to the first input optical port of the photonic integrated chip 400 , used to receive the light sent by the laser that does not carry a signal, that is, the light emitted by the laser enters the power divider through port 1 or port 2; port 1 is connected to

ports

3 and 4 respectively, that is, the light input by port 1 passes through the power divider Divided into 2 paths of light, output through 3 ports and 4 ports respectively; in the same way, the input light of 2 ports is divided into 2 paths of light by the power divider, and output through 3 ports and 4 ports respectively. The 3-port and the 4-port are respectively connected with the modulator, that is, the multi-path optical signals output by the power divider enter the modulator respectively for signal modulation to form signal light.

FIG. 7 is a schematic structural diagram of a power divider in an optical module according to an embodiment of the present disclosure. As shown in FIG. 7 , the power splitter includes a substrate 403 and a dual-core waveguide disposed on the substrate 403 , and the dual-core waveguide structure may be a strip-type waveguide or a ridge-type waveguide. The present disclosure takes a ridge waveguide as an example for description, including a slab structure of a ridge waveguide, the slab 404 is arranged on the substrate 403 , and the dual-core waveguide is arranged on the slab 404 .

The dual-core waveguide includes an input section waveguide and a power section waveguide that are integrally connected, and the distance between the first waveguide and the second waveguide of the input section waveguide is gradually reduced in the light propagation direction, so that the first waveguide and the first waveguide are connected by a single waveguide. The mode evolves into a dual-core waveguide mode, that is, the spacing between the first waveguide of the input section waveguide and the second waveguide gradually decreases from the front end to the rear end, and the single mode of the first waveguide or the second waveguide gradually transitions to dual-core mode. The mode of the waveguide enables the light input from a single waveguide to gradually evolve into a dual-core waveguide mode field, where both the first waveguide and the second waveguide have light energy in the dual-core waveguide mode field.

The widths of the first waveguide and the second waveguide of the input segment waveguide are different, and the widths of the two are gradually narrowed in the light propagation direction until the widths of the first waveguide and the second waveguide are the same, so that the first waveguide or the second waveguide has the same width. Light without signal input into the waveguide has the same power in the first waveguide as in the second waveguide. That is, the light input from the first waveguide is different from the light input from the second waveguide. When the light input from the first waveguide evolves from the single mode to the dual-core waveguide mode field, the state where the light input from the first waveguide evolves to the end of the input waveguide is different from that input from the second waveguide. The state of light evolution to the end of the waveguide of the input segment is also different.

The distance between the first waveguide and the second waveguide of the power segmented waveguide gradually increases in the direction of light propagation, so that the input light without signal is divided into two paths of light with the same power, which are respectively composed of the first waveguide and the second waveguide. Two waveguide outputs. That is, when the light from the end of the input segment waveguide is transmitted to the power segment waveguide, the power segment waveguide divides the light into two paths of light. Two waveguide outputs to realize the function of power division. And since the state of the light input by the first waveguide at the end of the input section waveguide is different from that of the light input by the second waveguide at the end of the input section waveguide, the light input by the first waveguide is in the first waveguide and the second waveguide of the power segment waveguide. The light respectively output by the waveguide is different from the light input by the second waveguide and the light output by the first waveguide and the second waveguide respectively in the work segmented waveguide, and light in different states is obtained.

In this example, the light input from the 1-port (the first waveguide of the input-segment waveguide) is output by 50% through the 3-port (the first waveguide of the power-segmented waveguide) and the 4-port (the second waveguide of the power-segmented waveguide). The phase difference of the two output lights is 180°; the light input from the 2-port (the second waveguide of the input section waveguide) outputs 50% of the light through the 3-port and 4-port, and the phase difference of the two output lights is 0 °.

FIG. 8 is a schematic diagram of a partition of a power divider in an optical module according to an embodiment of the present disclosure. As shown in FIG. 8 , in order to facilitate the power splitter to realize the light-splitting function from light to the photonic integrated chip 400 , the dual-core waveguide of the power splitter is divided into the first power splitting area, the second power splitting area, and the power splitting area along the light propagation direction. The third area, the fourth area of power division, and the fifth area of power division are connected in sequence. The input section waveguide is located in the first power division area and the second power division area, and the power section waveguide is located in the fourth power division area and the fifth power division area.

In this example, the first waveguide includes a first segment 405 , a second segment 406 , a third segment 407 , a fourth segment 408 and a fifth segment 409 connected in sequence, and the second waveguide includes a sixth segment 4010 , a seventh segment 4010 and a seventh segment connected in sequence. The segment 4011, the eighth segment 4012, the ninth segment 4013 and the tenth segment 4014, the first segment 405 of the first waveguide and the sixth segment 4010 of the second waveguide are located in the first area of power division, and are used to receive signals that do not carry signals respectively. Light; the second section 406 of the first waveguide and the seventh section 4011 of the second waveguide are located in the second power division region, and are used to evolve the first waveguide and the second waveguide from a single mode to a dual-core waveguide mode with the same width; the first The third section 407 of the first waveguide and the eighth section 4012 of the second waveguide are located in the third region of power division, which are used to stably transmit light without signals; the fourth section 408 of the first waveguide and the ninth section 4013 of the second waveguide Located in the fourth area of power division, the fifth section 409 of the first waveguide and the tenth section 4014 of the second waveguide are located in the fifth area of power division, and are used to divide the light without signal received by the first section or the second section into Two-way optical signal output.

Fig. 9 is a cross-sectional view along the A-A' direction in the power divider provided by the embodiment of the present disclosure. As shown in FIG. 9 , the width of the first section 405 of the first waveguide is different from the width of the sixth section 4010 of the second waveguide, and in the light propagation direction, the width of the first section 405 is different from the width of the sixth section 4010 In the light propagation direction, the distance between the first segment 405 and the sixth segment 4010 is gradually reduced, so that the mode fields of the first segment 405 and the sixth segment 4010 gradually evolve into dual-core waveguide mode fields.

In this example, the first section 405 of the first waveguide and the sixth section 4010 of the second waveguide are transition sections. To ensure low-loss transmission of the optical field, the lengths of the first section 405 and the sixth section 4010 may be 30-50 μm .

FIG. 10 is a cross-sectional view along the direction B-B' of the power divider provided by the embodiment of the present disclosure. As shown in FIG. 10 , the width of the second section 406 of the first waveguide and the width of the seventh section 4011 of the second waveguide both gradually decrease in the light propagation direction, until the width of the second section 406 is the same as the width of the seventh section 4011 . The widths are the same, and the spacing between the second segment 406 and the seventh segment 4011 may remain unchanged in the light propagation direction. That is, after the light enters the power splitter from the first section 405 or the sixth section 4010, the light gradually transitions to the dual-core waveguide mode field in the second region of the power division, and the light input from the single mode enters the first waveguide and the second waveguide respectively, Since the widths of the second segment 406 and the seventh segment 4011 are different, the light energy in the second segment 406 and the seventh segment 4011 are different until the light is transmitted to the ends of the second segment 406 and the seventh segment 4011 , the second segment 406 and the seventh segment 4011 have different light energy. The width of the end of 406 is the same as the width of the end of the seventh segment 4011, so the light energy is the same in both waveguides.

In the light propagation direction, the spacing between the second segment 406 and the seventh segment 4011 may also gradually decrease. The size of the distance between the second section 406 and the seventh section 4011 determines the optical band covered by the power divider. When the distance between the second section 406 and the seventh section 4011 is larger, the second area of power division can enter more wavelength bands When the distance between the second segment 406 and the seventh segment 4011 is small, only the light of a single wavelength band can be entered into the second region of power division. Therefore, by optimizing the size of the distance between the second section 406 and the seventh section 4011, the power splitter can cover the light of the O-band and the C-band at the same time. In this example, the distance between the second segment 406 and the seventh segment 4011 may be 150-200 nm.

In addition, the widths of the first segment 405 and the sixth segment 4010 are different, so that the light entering the first segment 405 is different from the light entering the sixth segment 4010. By optimizing the lengths of the second segment 406 and the seventh segment 4011, such that The lengths of the second segment 406 and the seventh segment 4011 reach a preset length, which can ensure that the light incident from the first segment 405 evolves into an odd mode at the ends of the second segment 406 and the seventh segment 4011 , that is, the light enters the second segment 406 At the end of the seventh segment 4011, light with opposite phases (one forward and one backward) is generated; the light incident from the sixth segment 4010 evolves into an even mode at the end of the second segment 406 and the seventh segment 4011, that is, the light enters the second segment 4011. The end of segment 406, seventh segment 4011 produces light of the same phase. In this example, the length between the second segment 406 and the seventh segment 4011 may be 250˜300 μm.

The distance between the second section 406 and the seventh section 4011 in the second power division area affects the length of the second section 406 and the seventh section 4011. If the distance between the two is large, the length of the two can be appropriately reduced; When the distance between the two is small, the length of the two can be appropriately increased, so that the wavelength of the light covered by the power divider can be changed.

Fig. 11 is a cross-sectional view of the C-C' direction in the power divider provided by the embodiment of the present disclosure. As shown in FIG. 11 , the third region of power division is the normal transmission region of the dual-core waveguide mode field. The width of the third section 407 of the first waveguide and the eighth section 4012 of the second waveguide are the same, and the distance between them is the same as The spacing between the second segment 406 and the seventh segment 4011 is the same, that is, the width remains unchanged, and the spacing remains unchanged, so as to stably transmit light.

In this example, the power division third region is the normal transmission region of the dual-core waveguide mode field, and the lengths of the third segment 407 and the eighth segment 4012 can be any value, such as 0-10 μm; the power division third region may not exist. , that is, the dual-core waveguide in the second power division area is directly connected to the dual-core waveguide in the fourth power division area to perform power division operation.

Fig. 12 is a sectional view of the D-D' direction in the power divider provided by the embodiment of the present disclosure, and Fig. 13 is a cross-sectional view of the E-E' direction of the power divider provided by the embodiment of the present disclosure. As shown in FIGS. 12 and 13 , the width of the fourth section 408 of the first waveguide and the width of the ninth section 4013 of the second waveguide both gradually increase in the same proportion in the light propagation direction, and in the light propagation direction, the The spacing between the fourth segment 408 and the ninth segment 4013 remains unchanged; the width of the fifth segment 409 of the first waveguide is the same as the width of the tenth segment 4014 of the second waveguide, and does not increase, and in the light propagation direction, the first The spacing between the fifth segment 409 and the tenth segment 4014 is gradually increased so that the first waveguide is gradually separated from the second waveguide. In this way, the light output from the input section of the waveguide gradually evolves into the single-waveguide mode of the fifth section 409 and the tenth section 4014 through the dual-core waveguide mode of the fourth section 408 and the ninth section 4013 to realize the function of power division. The fifth segment 409 and the tenth segment 4014 are output.

The lengths of the fourth segment 408 and the ninth segment 4013 in the fourth power division region need to be long enough to ensure low-loss transmission of the optical field. In this example, the lengths of the fourth segment 408 and the ninth segment 4013 may be 40˜50 μm.

Similarly, the lengths of the fifth section 409 and the tenth section 4014 in the fifth power division area also need to be long enough to ensure low-loss transmission of the optical field. In this example, the lengths of the fifth segment 409 and the tenth segment 4014 may be 30˜50 μm.

The power divider provided by the present disclosure divides the dual-core waveguide into a first power division zone, a power division second zone, a power division third zone, a power division fourth zone, and a power division fifth zone, and optimizes the design of the dual-core waveguide. The power is divided into the first area, the second area, the third area, the fourth area, and the fifth area. The width, spacing and length of the first waveguide and the second waveguide, The optical signal beam splitting with a wide spectral band is realized, and the output optical signals have a specific phase relationship.

FIG. 14 is a schematic diagram of an optical transmission path in a power splitter provided by an embodiment of the present disclosure. As shown in FIG. 14 , when the light emitted by the light source 500 enters through the first section 405 of the first waveguide, after the light passes through the first section 405 in the first region of power division, the light evolves from the single mode of the first waveguide to the dual-core waveguide. Mode 1: After passing through the second section 406 and the seventh section 4011 in the power division second area, the mode 1 of the dual-core waveguide evolves to the dual-core waveguide mode of the same width, and the light evolves to the second section 406 and the seventh section. The odd mode at the end of the segment 4011; and then pass through the dual-core waveguide of the third segment 407 and the eighth segment 4012 in the third area of the power division; The transmission of the fifth section 409 and the tenth section 4014 in the fifth area realizes the function of power division, and the output optical power of the two paths is the same, and the phase difference is 180 degrees.

FIG. 15 is a schematic diagram of another optical transmission path in the power divider provided by the embodiment of the present disclosure. As shown in FIG. 15 , when the light emitted by the light source 500 enters through the sixth section 4010 of the second waveguide, after the light passes through the sixth section 4010 in the first region of power division, the light evolves from the single mode of the second waveguide to the dual-core waveguide. Mode 2: After passing through the second section 406 and the seventh section 4011 in the power division second area, the mode 2 of the dual-core waveguide evolves to the dual-core waveguide mode of the same width, and the light evolves to the second section 406 and the seventh section. The even mode at the end of the segment 4011; and then pass through the dual-core waveguide of the third segment 407 and the eighth segment 4012 in the third area of the power division; The transmission of the fifth section 409 and the tenth section 4014 in the fifth area realizes the function of power division, and the output optical power of the two paths is the same, and the phase difference is 0 degrees.

In the embodiments of the present disclosure, by using the solution of photonic integrated chips, the traditional complex spatial optical system is replaced, the device system is simplified, the device packaging is simpler, and the miniaturization and low-cost development of the optical module are facilitated. In addition, by optimizing the design of the first, second, third, fourth, fifth, and sixth, seventh, eighth, and sixth sections of the second waveguide in the dual-core waveguide The width and length of the ninth and tenth sections, as well as the distance between the first and sixth, the second and seventh, the third and eighth, the fourth The distance between the ninth section and the fifth section and the tenth section realizes the optical signal beam splitting of the wide-spectrum waveguide of the power splitter, so that the power splitter can cover the O-band and C-band at the same time. light, and have a specific phase relationship between the output optical signals.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, but not to limit them; although the present disclosure has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be Modifications are made to the technical solutions described in the foregoing embodiments, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions depart from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

An optical module, characterized in that it includes:

circuit board;

a light source, electrically connected to the circuit board, for emitting light that does not carry a signal;

The photonic integrated chip is electrically connected to the circuit board, and the input optical port of the photonic integrated chip is provided with a power splitter, which is used to divide the light that does not carry a signal into multiple paths of light; the photonic integrated chip divides the The multiplexed light is modulated into signal light and the signal light is output through the output optical port of the photonic integrated chip;

The power divider includes:

substrate;

The dual-core waveguide is arranged on the substrate, and includes an input section waveguide and a power section waveguide that are integrally connected, and the distance between the first waveguide and the second waveguide of the input section waveguide gradually decreases in the light propagation direction, so as to evolve the first waveguide and the first waveguide from a single mode into a dual-core waveguide mode; the widths of the first waveguide and the second waveguide are different, and the widths of the two gradually change in the light propagation direction narrow until the width of the first waveguide and the second waveguide are the same, so that the light without signal input by the first waveguide or the second waveguide The power on the second waveguide is the same;

The distance between the first waveguide and the second waveguide of the power segmented waveguide gradually increases in the light propagation direction, so that the input light without a signal is divided into two paths of light with the same power, which are separated by The light output from the first waveguide and the second waveguide has a specific phase.
The optical module according to claim 1, wherein the power divider is divided into a first power division area, a second power division area, a third power division area, and a fourth power division area along its light propagation direction and the fifth region of power division, the input segment waveguide is located in the first region of power division and the second region of power division, and the power segment waveguide is located in the fourth region of power division and the fifth region of power division Area;

The first waveguide includes a first segment, a second segment, a third segment, a fourth segment, and a fifth segment connected in sequence, and the second waveguide includes a sixth segment, a seventh segment, an eighth segment, an ninth and tenth paragraphs;

The first section of the first waveguide and the sixth section of the second waveguide are located in the first power division region, and are used for respectively receiving the light without the signal;

The second section of the first waveguide and the seventh section of the second waveguide are located in the second power division region, and are used to evolve the first waveguide and the second waveguide from a single mode to a same width. Dual core waveguide mode;

The third section of the first waveguide and the eighth section of the second waveguide are located in the third power division area, and are used for stably transmitting the light that does not carry a signal;

The fourth section of the first waveguide and the ninth section of the second waveguide are located in the fourth power division region, and the fifth section of the first waveguide and the tenth section of the second waveguide are located in the The fifth area of power division is used for dividing the light without signal received by the first section or the second section into two paths of optical signal output.
The optical module according to claim 2, wherein the width of the first segment of the first waveguide is different from the width of the sixth segment of the second waveguide, and in the light propagation direction, the first The width of the segment is the same as the width of the sixth segment; in the light propagation direction, the distance between the first segment and the sixth segment is gradually reduced.
The optical module according to claim 2, wherein the width of the second segment of the first waveguide and the width of the seventh segment of the second waveguide both gradually decrease in the light propagation direction until The width of the second segment is the same as the width of the seventh segment; in the light propagation direction, the distance between the second segment and the seventh segment is the same as the first segment and the seventh segment. The ends of the six segments are equally spaced.
The optical module according to claim 2, wherein the width of the second segment of the first waveguide and the width of the seventh segment of the second waveguide both gradually decrease in the light propagation direction until The width of the second segment is the same as the width of the seventh segment; in the light propagation direction, the spacing between the second segment of the first waveguide and the seventh segment of the second waveguide decreases gradually small.
The optical module according to claim 4 or 5, wherein the lengths of the second section of the first waveguide and the seventh section of the second waveguide are both preset lengths, so that the first The light input from the segment evolves into an odd mode at the end of the second segment and the seventh segment, and is divided into two paths of light with a phase difference of 180 degrees in the fifth area of the power division;

And, the light input from the sixth section evolves into an even mode at the end of the second section and the seventh section, and is divided into two paths of light with a phase difference of 0 degrees in the fifth power division area.
The optical module according to claim 2, wherein the width of the third section of the first waveguide and the eighth section of the second waveguide are the same, and the distance between them is the same as the second section, The intervals between the seventh segments are the same.
The optical module according to claim 2, wherein the width of the fourth section of the first waveguide and the width of the ninth section of the second waveguide both gradually increase at the same ratio in the light propagation direction ; In the light propagation direction, the spacing between the fourth segment and the ninth segment is the same as the spacing between the third segment and the eighth segment.
The optical module according to claim 2, wherein the width of the fifth segment of the first waveguide is the same as the width of the tenth segment of the second waveguide; in the light propagation direction, the The spacing between the fifth segment and the tenth segment gradually increases.