Flexible optical waveguide optical module

Abstract

The flexible optical waveguide optical module comprises a transmitting end, a receiving end and a controller which are used in cooperation. A plurality of transmitting ends and a plurality of receiving ends are combined to form three groups of transmitting and receiving integrated modules, and the three groups of transmitting and receiving integrated modules are communicated with the optical waveguide; based on an intrinsic mode analysis method, establishing a waveguide bandwidth characteristic theoretical model, and realizing accurate calculation and simulation of waveguide bandwidth; designing an ultra-high bandwidth polymer optical waveguide insensitive to excitation conditions; the design of a waveguide assembly for replacing FA to perform 12-channel optical path coupling in the optical module is realized; large-size multi-channel waveguide photoetching based on light-induced in-situ refractive index regulation and control inhibits waveguide defects such as surface roughness and side wall roughness, reduces waveguide transmission loss and improves waveguide bandwidth; on the basis of a high-precision laser processing technology, optical waveguide end face processing and cutting with low surface roughness and low scattering loss are carried out.

Description

Technical Field

[0001] This invention relates to optoelectronic communication technology and its equipment, specifically a flexible optical waveguide module. Background Technology

[0002] The flexible optical waveguides currently in use have issues that need to be addressed: 1) High power consumption, generally 12W, and some even reach 18W; 2) Large bending radius, generally greater than or equal to 5mm; 3) The operating temperature must not exceed 80°C.

[0003] These defects have severely hampered the development of flexible optical waveguides.

[0004] Therefore, it is necessary to provide a flexible optical waveguide module to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a flexible optical waveguide module with a waveguide channel spacing control accuracy of ±5 μm; waveguide length ≥100 mm and waveguide loss ≤0.2 dB / cm at 850nm wavelength; and interfacing loss between waveguide and quartz fiber components ≤0.6 dB. This waveguide-based optical module has a total of 24 channels, an operating temperature of -40℃ to 85℃, and a power consumption not exceeding 7W. It exhibits significant advantages in channel integration, power consumption, operating temperature, and hermeticity. This invention provides the industry with a novel short-distance, high-speed transmission optical module, filling the gap in centimeter- to meter-level high-speed, high-density flexible interconnect technology.

[0006] The technical solution is as follows: A flexible optical waveguide module includes a transmitter, a receiver, and a controller used in conjunction. The transmitting end includes a driver chip, and the receiving end includes an amplification chip for electrical signals; The number of transmitters and receivers is several, which are combined to form three sets of integrated transmitter and receiver modules. The three sets of integrated transmitter and receiver modules are connected to the optical waveguide. The transmitter also includes a VCSEL laser, which converts the input electrical signal into an optical signal output actuator; The receiver also includes a PD array, which is used as an actuator to convert the input optical signal into a differential signal output. After the integrated transmitter and receiver module is coupled with the optical waveguide, an optical fiber is not thrown out; the three sets of transmitter and receiver components are paralleled, combining 12 transmitters and 12 receivers together; By configuring the MCU's state, the MCU can correctly control the driver chip's operating state through the I2C interface. To ensure the stability of the product's luminous power across the entire temperature range, temperature compensation is also required. Based on the intrinsic mode analysis method, a theoretical model of waveguide bandwidth characteristics is established to achieve accurate calculation and simulation of waveguide bandwidth; an ultra-high bandwidth polymer optical waveguide that is insensitive to excitation conditions is designed; and a waveguide component that replaces the FA for 12-channel optical path coupling is designed in an optical module. A method for suppressing waveguide defects such as surface roughness and sidewall roughness, reducing waveguide transmission loss and increasing waveguide bandwidth based on photo-induced in-situ refractive index modulation of large-size multi-channel waveguides; achieving waveguide channel spacing control accuracy of ±5 μm; waveguide loss ≤0.2 dB / cm at a waveguide length ≥100 mm and a wavelength of 850 nm; waveguide operating temperature -40℃~85℃. Based on high-precision laser processing technology, the end face of the optical waveguide with low surface roughness and low scattering loss is processed and cut to achieve a docking loss of ≤0.6 dB between the waveguide component and the quartz fiber component.

[0007] Furthermore, the MCU status configuration process includes: Port configuration; ADC initialization, transmitter initialization, receiver initialization; Set the loop conditions; perform transmit enable control, receive enable control, FAULTA indicator reading, and SD indicator reading; ADC data acquisition: Iavg and Imod algorithm design, Iavg and Imod writing to RHXT8204.

[0008] Furthermore, the integrated transmitter and receiver module is mounted on a plastic protective cover. PCB board A and PCB board B are mounted above and below the plastic protective cover, respectively. At the location of the integrated transmitter and receiver module on the plastic protective cover, there are also insulating pads and high-efficiency heat sinks. The insulating pads are ceramic pads, and the high-efficiency heat sinks are tungsten copper heat sinks.

[0009] Furthermore, the electrical interface uses a 10×20 crimp-type spring connector. During use, the bottom of the module fits tightly against the user board, and screws are used to lock the product onto the user board.

[0010] Furthermore, the transmitter uses the XY5924 from XinYun Optoelectronics as the VCSEL driver chip, which simultaneously drives four lasers to emit light, supports a maximum signal transmission rate of 28.05Gbps, and can output a maximum average current of 15mA and a modulation current of 12.8mA per channel.

[0011] Furthermore, the receiver selects the XY5424 from Chipwin Optoelectronics as the amplification chip for electrical signals; Furthermore, GigaDevice's GD32E series MCU was selected as the controller. It is small in size, which is convenient for PCB layout; it contains 64KB Flash space, 8KB RAM space and 8KB ROM space, which can meet the needs of large-capacity code design; the operating temperature range is -40℃ to +105℃, which can meet the wide operating temperature range design of optical modules.

[0012] Furthermore, the REXT pin of the driver chip and the RSSI pin and I2C communication pin of the amplifier chip are connected to the port of the MCU.

[0013] Compared with existing technologies, this invention achieves a waveguide channel spacing control accuracy of ±5 μm; waveguide loss ≤0.2 dB / cm at a wavelength of 850nm and a waveguide length ≥100mm; and docking loss between waveguide components and quartz fiber components ≤0.6 dB. The waveguide-based optical module has a total of 24 channels, an operating temperature of -40℃ to 85℃, and a power consumption not exceeding 7W. It exhibits significant advantages in channel integration, power consumption, operating temperature, and hermeticity. This invention provides the industry with a novel short-distance, high-speed transmission optical module, filling the gap in centimeter- to meter-level high-speed, high-density flexible interconnect technology. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the integrated transmitter and receiver module.

[0015] Figure 2 This is the MCU's status configuration process.

[0016] Figure 3 This is a schematic diagram of the configuration of the integrated transmitter and receiver module. Detailed Implementation

[0017] Example:

[0018] Please see Figure 1-3 This embodiment demonstrates a flexible optical waveguide module, including a transmitter 100, a receiver 200, and a controller 500 used in conjunction. The transmitter 100 includes a driver chip, and the receiver 200 includes an amplification chip for electrical signals; The number of transmitters 100 and receivers 200 is several, which are combined to form three sets of integrated transmitter and receiver modules 300. The three sets of integrated transmitter and receiver modules 300 are connected to the optical waveguide 400. The transmitter 100 also includes a VCSEL laser, which is used to convert the input electrical signal into an optical signal output actuator; The receiver 200 also includes a PD array, which is used as an actuator to convert the input optical signal into a differential signal output. After the integrated transmitter and receiver module 300 and the optical waveguide optical path coupling 400 are coupled together, an optical fiber is thrown out; the three sets of transmitter and receiver components are paralleled to connect 12 transmit channels and 12 receive channels together. By configuring the MCU's state, the MCU can correctly control the driver chip's operating state through the I2C interface. To ensure the stability of the product's luminous power across the entire temperature range, temperature compensation is also required. Based on the intrinsic mode analysis method, a theoretical model of waveguide bandwidth characteristics is established to achieve accurate calculation and simulation of waveguide bandwidth; an ultra-high bandwidth polymer optical waveguide that is insensitive to excitation conditions is designed; and a waveguide component that replaces the FA for 12-channel optical path coupling is designed in an optical module. A method for suppressing waveguide defects such as surface roughness and sidewall roughness, reducing waveguide transmission loss and increasing waveguide bandwidth based on photo-induced in-situ refractive index modulation of large-size multi-channel waveguides; achieving waveguide channel spacing control accuracy of ±5 μm; waveguide loss ≤0.2 dB / cm at a waveguide length ≥100 mm and a wavelength of 850 nm; waveguide operating temperature -40℃~85℃. Based on high-precision laser processing technology, the end face of the optical waveguide with low surface roughness and low scattering loss is processed and cut to achieve a docking loss of ≤0.6 dB between the waveguide component and the quartz fiber component.

[0019] The MCU status configuration process includes: Port configuration; ADC initialization, transmitter initialization, receiver initialization; Set the loop conditions; perform transmit enable control, receive enable control, FAULTA indicator reading, and SD indicator reading; ADC data acquisition: Iavg and Imod algorithm design, Iavg and Imod writing to RHXT8204.

[0020] The integrated transmitter and receiver module 300 is mounted on a plastic protective cover 1. PCB board A2 and PCB board B3 are mounted above and below the plastic protective cover 1, respectively. At the location of the integrated transmitter and receiver module 300 on the plastic protective cover 1, there is also an insulating pad 5 and a high-efficiency heat sink 6. The insulating pad 5 is a ceramic pad and the high-efficiency heat sink 6 is a tungsten copper heat sink.

[0021] The electrical interface uses a 10×20 crimp spring connector. During use, the bottom of the module fits tightly against the user board, and screws are used to lock the product onto the user board.

[0022] The transmitter uses the XY5924 from XinYun Optoelectronics as the VCSEL driver chip, which simultaneously drives four lasers to emit light. It supports a maximum signal transmission rate of 28.05Gbps and can output a maximum average current of 15mA and a modulation current of 12.8mA per channel.

[0023] The receiver uses the XY5424 chip from XinYun Optoelectronics as the amplification chip for electrical signals. The GigaDevice GD32E series MCU was selected as the controller. It is small in size and easy to lay out on the PCB. It contains 64KB Flash space, 8KB RAM space and 8KB ROM space, which can meet the needs of large-capacity code design. The operating temperature range is -40℃ to +105℃, which can meet the wide operating temperature range design of optical modules.

[0024] The REXT pin of the driver chip and the RSSI pin and I2C communication pin of the amplifier chip are connected to the MCU port.

[0025] Also includes: Addressing the challenge of replacing traditional FA (ribbon fiber) with flexible optical waveguide components in optical modules from scratch, solving the problem of efficient coupling between flexible optical waveguide components and optical chips is key to achieving efficient photoelectric conversion.

[0026] Through structural and material property analysis and application research of flexible optical waveguides, the pre-application development of flexible waveguides in modules has been overcome, achieving a bending radius of ≤2mm. Utilizing optical simulation technology, a method of adjusting the overall optical path by introducing an optical adapter between the waveguide and the PD has been innovatively developed, enabling the development of diverse optical micron lens array technology. This completely solves the problem of adjusting the spot size and shape, thereby ensuring efficient light coupling.

[0027] By employing a high-precision image alignment system and real-time digital sampling technology, and through the development of a two-stage high-precision identification and correction positioning technology, high-precision alignment of the waveguide and lens combination is achieved, ensuring that the displacement deviation between the lens and the waveguide in the X direction is ≤5μm and the displacement deviation in the Y direction is ≤5μm. Utilizing a 0.1μm high-precision micro-nano assembly process, ultra-precision bonding of the flexible waveguide and lens is finally achieved.

[0028] By utilizing micron-level lens array technology and through optical modeling and simulation analysis, the size and shape of the waveguide light spot on the optical surface are precisely adjusted to better match the photosensitive surface of the photodiode (PD). Simultaneously, an innovative photosensitive adjustment technology for the receiver is developed. By adjusting the receiver design, increasing the area of ​​the photosensitive surface and the distance between the pads and the photosensitive surface, the requirements for coupling accuracy are reduced, and the coupling efficiency between the flexible waveguide component and the optical chip is improved, achieving a coupling efficiency of ≥80%. This ensures that the product's output optical power is ≥-4dBm and the signal sensitivity is ≤-7dBm. This breakthrough overcomes the technical challenge of replacing traditional ribbon fiber optic cables (FAs) with optical waveguide components from scratch, enabling flexible optical interconnection in confined spaces.

[0029] Using flexible waveguide components to replace traditional ribbon fibers not only effectively achieves optical path coupling in the module, but also has excellent flexibility, with a bending radius far superior to that of ribbon fibers, avoiding stress concentration problems caused by excess ribbon fiber length; it reduces the risk of fiber breakage, improves the performance and stability of optical interconnects, and makes it highly advantageous in space-constrained environments, allowing it to operate in more compact spaces.

[0030] We developed a multi-channel encapsulation and high-efficiency heat dissipation technology for laser chips. By optimizing the design of parallel interconnect optical paths, we reduced signal interference and noise suppression between channels. Then, we adopted a tungsten copper heat dissipation design (with a thermal conductivity more than 3 times higher than that of traditional copper blocks), which allows multiple COS to be integrated on a single TEC. By coupling and aligning with array optical fibers and microlenses, we formed a multi-channel encapsulation, achieving a channel count of ≥12.

[0031] Simulation and layout design were conducted in a simulation environment to study the electro-optical characteristics of the VCSEL high-speed light source and the high-speed photoelectric response characteristics of the detector array. The impact of the light source injection method on the transmission bandwidth of the multimode fiber optic transmission system was simulated. Through modeling and simulation analysis, the transmission loss and bandwidth requirements of the system were calculated, and the design of the parallel interconnect optical path was optimized to reduce signal interference between channels and noise suppression. Simultaneously, a tungsten-copper block with high thermal conductivity and low thermal expansion coefficient was embedded inside the PCB to ensure good heat dissipation. Its thermal conductivity is more than three times higher than that of traditional copper blocks, preventing optical path deviation due to temperature changes. In the structural design, the optoelectronic chip, which has the highest power consumption in the optical device module, was mounted on the inner side of the tungsten-copper block. During module installation, the outer side of the tungsten-copper block directly contacts the upper shell of the optical device module, allowing the heat generated by the optoelectronic chip to be efficiently conducted to the upper shell, improving the VCSEL light source and detector array speed and reducing product power consumption. Laser chips are mounted onto aluminum nitride heat sinks using gold-tin solder to form COS (Chip On Submount). COS testing and aging equipment is used to perform LIV (Light Power-Current-Voltage) curve and spectral testing on the COS, and the chips are classified according to their optical power and spectrum. Multiple COS are then integrated and assembled onto the same TEC carrier. Assembly precision is ensured by placing a heat sink with a micron-level precision metal pattern on the TEC. The TEC and other components are then assembled into a metal housing and aligned with the array fiber and microlenses to form a multi-channel encapsulation, achieving a channel count of ≥12.

[0032] We developed a two-stage high-precision image recognition, correction, positioning, and micro / nano bonding technology. This solved the problem of mounting / coupling displacement and spacing deviation caused by material tolerances and alignment errors between the flexible optical waveguide, lens array, and chip, achieving a mounting accuracy of ≤3μm, thus laying the foundation for the industrial production of the target product.

[0033] Adopt optical simulation nano-selection technology to solve the problem of pitch deviation caused by material tolerance. Through innovative research and development of a two-stage high-precision image recognition and correction positioning technology, identify the edge of the selected material, and establish the starting origin coordinates for mounting / coupling based on this. Then, use a low-magnification image to recognize the outer contour of the micro-lens / optical chip. Next, use a high-precision device to pick up the optical chip from the storage box and place it on the transfer table, while correcting the placement position of the chip. Then, use a high-precision image recognition system with a visual resolution of 1μm to establish the identification line of the chip component using the identification points of the first and fourth channels of the optical chip array. Through a customized high-precision coupling table designed independently, use a micron-level nozzle of a high-precision linear motor to pick up the center of the chip, and then mount the chip to the specified position. Solve the problem of pitch deviation caused by the deviation of accurate alignment in mounting / coupling, and achieve efficient mounting or coupling of precise alignment between the flexible waveguide-lens-chip.

[0034] Improve the device miniaturization design and high-density packaging technology. Through the multi-core assembly integration method, improve the installation density, and design the "pin" shape arrangement of different components and chips to achieve ultra-small and high-density packaging of the optical module.

[0035] The module adopts a "pin" shape design inside to improve the utilization efficiency of the internal space of the module. Efficiently layout three groups of optoelectronic chips on the PCB within a limited space, ensure the shortest routing path for 12 pairs of high-speed differential signals, and at the same time ensure that the insertion return loss index of the high-speed electrical signals of the optical device module is qualified; also reserve the best design shape for the waveguide to ensure the simplest waveguide design. At the same time, research on anti-interference and anti-aging technologies will be carried out to ensure the high reliability of the system design, and finally achieve miniaturized and high-density packaging of the device.

[0036] Compared with the existing technology, when applying this invention, the control accuracy of the waveguide channel pitch is ±5 μm; when the waveguide length ≥ 100mm and the wavelength is 850nm, the waveguide loss ≤ 0.2 dB / cm; the butt joint loss between the waveguide component and the quartz fiber component ≤ 0.6 dB; for the optical module using the waveguide solution, the total number of channels is 24, the working temperature is -40°C to 85°C, and the power is not more than 7W; it has obvious advantages in aspects such as channel number integration, power consumption, working temperature, and airtightness; provide a new type of optical module for short-distance high-speed transmission for the industry, filling the technical gap of centimeter-to-meter-level high-speed and high-density flexible interconnection in the industry.

[0037] For ordinary technical personnel in this field, without departing from the creative concept of this invention, several deformations and improvements can still be made, and these all belong to the protection scope of this invention.

Claims

1. A flexible optical waveguide module, characterized in that: This includes the transmitter, receiver, and controller used in conjunction with the device; The transmitting end includes a driver chip, and the receiving end includes an amplification chip for electrical signals; The number of transmitters and receivers is several, which are combined to form three sets of integrated transmitter and receiver modules. The three sets of integrated transmitter and receiver modules are connected to the optical waveguide. The transmitter also includes a VCSEL laser, which converts the input electrical signal into an optical signal output actuator; The receiver also includes a PD array, which is used as an actuator to convert the input optical signal into a differential signal output. After the integrated transmitter and receiver module is coupled with the optical waveguide, an optical fiber is not thrown out; the three sets of transmitter and receiver components are paralleled, combining 12 transmitters and 12 receivers together; By configuring the MCU's state, the MCU can correctly control the driver chip's operating state through the I2C interface. To ensure the stability of the product's luminous power across the entire temperature range, temperature compensation is also required. Based on intrinsic mode analysis, a theoretical model of waveguide bandwidth characteristics is established to achieve accurate calculation and simulation of waveguide bandwidth; an ultra-high bandwidth polymer optical waveguide that is insensitive to excitation conditions is designed; and a waveguide component that replaces the FA for 12-channel optical path coupling is designed in an optical module. A method for suppressing waveguide defects such as surface roughness and sidewall roughness, reducing waveguide transmission loss and increasing waveguide bandwidth based on photo-induced in-situ refractive index modulation of large-size multi-channel waveguides; achieving waveguide channel spacing control accuracy of ±5 μm; waveguide loss ≤0.2 dB / cm at a waveguide length ≥100 mm and a wavelength of 850 nm; waveguide operating temperature -40℃~85℃. Based on high-precision laser processing technology, the end face of the optical waveguide with low surface roughness and low scattering loss is processed and cut to achieve a docking loss of ≤0.6 dB between the waveguide component and the quartz fiber component.

2. The flexible optical waveguide module according to claim 1, characterized in that: The MCU status configuration process includes: Port configuration; ADC initialization, transmitter initialization, receiver initialization; Set the loop conditions; perform transmit enable control, receive enable control, FAULTA indicator reading, and SD indicator reading; ADC data acquisition: Iavg and Imod algorithm design, Iavg and Imod writing to RHXT8204.

3. The flexible optical waveguide module according to claim 2, characterized in that: The integrated transmitter and receiver module is mounted on a plastic protective cover. PCB board A and PCB board B are mounted above and below the plastic protective cover, respectively. At the location of the integrated transmitter and receiver module on the plastic protective cover, there are also insulating pads and high-efficiency heat sinks. The insulating pads are ceramic pads, and the high-efficiency heat sinks are tungsten copper heat sinks.

4. The flexible optical waveguide module according to claim 3, characterized in that: The electrical interface uses a 10×20 crimp spring connector. During use, the bottom of the module fits tightly against the user board, and screws are used to lock the product onto the user board.

5. A flexible optical waveguide module according to claim 4, characterized in that: The transmitter uses the XY5924 from XinYun Optoelectronics as the VCSEL driver chip, which simultaneously drives four lasers to emit light. It supports a maximum signal transmission rate of 28.05Gbps and can output a maximum average current of 15mA and a modulation current of 12.8mA per channel.

6. A flexible optical waveguide module according to claim 5, characterized in that: The receiver uses the XY5424 chip from XinYun Optoelectronics as the amplification chip for electrical signals.

7. A flexible optical waveguide module according to claim 6, characterized in that: The GigaDevice GD32E series MCU was selected as the controller. It is small in size and easy to lay out on the PCB. It contains 64KB Flash space, 8KB RAM space and 8KB ROM space, which can meet the needs of large-capacity code design. The operating temperature range is -40℃ to +105℃, which can meet the wide operating temperature range design of optical modules.

8. A flexible optical waveguide module according to claim 7, characterized in that: The REXT pin of the driver chip and the RSSI pin and I2C communication pin of the amplifier chip are connected to the MCU port.

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