Single-wave 100G long-distance transmission optical module
By adopting DSP chip and coaxial package design in the 100G optical module, combined with SOA and EML control circuits, the cost and complexity of the existing 100G optical module is solved, and efficient single-wave 100G long-distance transmission and spectrum efficiency are achieved. Improvement provides compatibility for future high-bandwidth networks.
Patent Information
- Application Number
- CN202420245834.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-01
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2034-02-01
AI Technical Summary
The existing 100G optical modules rely on parallel or wavelength division multiplexing of 4 channels of 25G optical channels, resulting in the need of multiple expensive optical devices and complex packaging, which increases cost and power consumption, making it difficult to meet low-cost and efficient network transmission. need.
A single-wave 100G long-distance optical transmission module was designed, and a DSP chip was used to convert 4 25G electrical signals into a single-wave 100G PAM4 optical signals. The light transmitting and receiving units were coaxially packaged, with built-in SOA chip for amplification, combined with TEC driver Circuits and EML control circuits realize signal processing and efficient management of optical components.
It effectively reduces the internal optical complexity and cost of optical modules, improves production yield and structural flexibility, improves transmission sensitivity and spectrum efficiency, supports long-distance transmission and provides compatibility for future high-bandwidth networks.
Smart Images
Figure CN222262735U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of optical communication, and in particular to a single-wavelength 100G long-distance transmission optical module. Background Art
[0002] In recent years, with the rapid development of data centers and cloud computing, the traffic of optical communication networks has continued to grow rapidly, and the global demand for high-speed network equipment has also increased. The commissioning of more network equipment has caused the operating costs of various telecom operators to increase. Therefore, the need to use high-speed optical modules to increase network transmission capacity at a low cost is very urgent.
[0003] In order to better adapt to the comprehensive bearer needs of 5G and dedicated line services, my country's operators have proposed a variety of 5G bearer technology solutions, mainly including sliced packet network (SPN), OTN optimized for mobile bearer (M-OTN), and IP RAN enhanced + optical layer. According to the "White Paper on 5G Bearer Network Architecture and Technical Solutions", 100G optical modules will be widely used in the metropolitan access layer.
[0004] Currently, 100G optical modules have become the mainstream in the market. Modules such as 100GSR4, LR4, CWDM4 and ER4 all rely on 4 25G optical channels in parallel or through wavelength division multiplexing for transmission. Each channel requires separate transmitting and receiving devices. They all require relatively expensive optical devices and packaging, which places high demands on the power consumption, spatial layout and cost of the optical modules.
[0005] The 100G single-wavelength optical module uses a DSP chip to convert four 25G electrical signals into a single-wavelength 100G PAM4 optical signal to achieve data transmission. The optical transmitting and receiving units are reduced from four to one, effectively reducing the internal optical complexity of the optical module. Due to the reduction in the number of components, the packaging form of the optical device has more options.
[0006] Therefore, based on the 100G Lambda MSA multi-source agreement, studying a single-wavelength 100G optical module that supports long-distance transmission will effectively alleviate the growing demand for network transmission capacity and low-cost operations, and play a role in facilitating the future transition from 100G to 200G and 400G. Utility Model Content
[0007] In order to meet the current demand for cost reduction and be compatible with 200G / 400G networking connections in the future, the utility model provides a single-wavelength 100G long-distance transmission optical module. The specific technical solution is as follows:
[0008] A single-wavelength 100G long-distance transmission optical module, the optical module includes an MCU main control unit, a DSP chip, an optical receiving unit, an optical transmitting unit, multiple functional circuits and an electrical interface, the DSP chip is respectively connected to the MCU main control unit, the electrical interface, the optical receiving unit and the optical transmitting unit, the MCU main control unit is connected to the electrical interface and the multiple functional circuits, and the multiple functional circuits include a TEC drive circuit, an EML control circuit, an SOA control circuit, and an optical power sampling circuit.
[0009] Furthermore, the optical module also includes a slow start unit and a power management unit, the power management unit includes multiple DC-DC step-down circuits, the input end of the slow start unit is connected to the electrical interface, the input end of the power management unit is connected to the output end of the slow start unit, and the output end of the power management unit is connected to the DSP chip and the multiple functional circuits.
[0010] Furthermore, the output ends of the SOA control circuit and the optical power sampling circuit are respectively connected to the light receiving unit, the devices in the light receiving unit are coaxially packaged, and the light receiving unit includes a semiconductor optical amplifier, a photodetector, a transimpedance amplifier, a semiconductor cooler and an optical element.
[0011] Furthermore, the SOA control circuit includes a DC drive chip and a peripheral circuit, and the DC drive chip is connected to the MCU main control unit via an IIC interface.
[0012] Furthermore, the output end of the EML control circuit is connected to the light emitting unit, the components in the light emitting unit are coaxially packaged, and the light emitting unit includes an EML laser, a semiconductor cooler and an optical element.
[0013] Furthermore, the output end of the TEC driving unit is connected to the light emitting unit and the light receiving unit respectively, and the TEC driving unit includes two TEC driving chips, a TOSA temperature sampling circuit and a ROSA temperature sampling circuit.
[0014] Furthermore, the DSP chip includes a receiving clock recovery circuit, a transmitting clock recovery circuit, a crystal oscillator circuit, a digital core processing circuit, and a signal output circuit.
[0015] Furthermore, the MCU main control unit includes an MCU chip and an analog DAC circuit, and the MCU chip is connected to the electrical interface via an IIC interface.
[0016] Furthermore, the MCU chip is connected to the EN pin of the DC-DC chip in the DC-DC buck circuit.
[0017] Furthermore, the MCU chip is connected to the EN pin of the EML control chip in the EML control circuit.
[0018] The utility model provides a single-wavelength 100G long-distance transmission optical module, which has the following beneficial effects:
[0019] 1. The utility model provides a single-wavelength 100G long-distance transmission optical module, in which both the optical emitting unit and the optical receiving unit adopt a coaxial packaging structure, thereby improving the production yield of the optical emitting unit and the optical receiving unit, reducing the size of the device while also improving the flexibility of the chip layout within the structure.
[0020] 2. The utility model provides a single-wavelength 100G long-distance transmission optical module. The optical receiving unit has a built-in SOA chip to amplify the incident light, greatly improving the sensitivity range of the product receiving end. At the same time, it also provides a design idea for subsequent single-wavelength 100G products with larger transmission distances.
[0021] 3. The utility model provides a single-wavelength 100G long-distance transmission optical module, which uses a DSP chip for signal processing. In addition to the clock recovery function provided by CDR, it can also perform dispersion compensation, remove noise, nonlinear interference and other factors, and support high-order modulation formats to improve spectrum efficiency. It can solve the device and channel transmission effects, handle the signal-to-noise ratio problem, and make the system's transmission performance more stable. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 The utility model provides a single-wavelength 100G long-distance transmission optical module. DETAILED DESCRIPTION
[0023] The following will be combined with the accompanying drawings provided by the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. According to the following description, the advantages and features of the utility model will be clearer. It should be noted that the drawings are all in a very simplified form and are not in precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the utility model.
[0024] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connection" and "connected" should be interpreted in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0025] In the description of the present invention, terms such as "upper", "lower", "left", "right", "front", "back", "center", "horizontal", "vertical", "top", "bottom", "inside" and "outside" and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of description and simplification of operation, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.
[0026] Embodiment: This embodiment provides a single-wavelength 100G long-distance transmission optical module, see Figure 1 As shown, the module includes a DSP chip, an MCU main control unit, a light emitting unit (TOSA), a light receiving unit (ROSA), multiple functional circuits, a power management unit, a slow start unit, and an electrical interface. One of the two opposite sides of the DSP chip is connected to the electrical interface, and the other side is connected to the light emitting unit and the light receiving unit. At the same time, the DSP chip is connected to the MCU main control unit and the power management circuit. The MCU main control unit is connected to the electrical interface and multiple functional circuits. The multiple functional circuits include a TEC drive circuit, an EML control circuit, an SOA control circuit, and a received optical power sampling circuit. The output end of the TEC drive circuit is respectively connected to the light receiving unit and the light emitting unit, the output end of the EML control circuit is connected to the light emitting unit, the output end of the SOA control circuit and the received optical power sampling circuit is connected to the light receiving unit, the input end of the slow start circuit is connected to the electrical interface, and the output end is connected to the power management unit.
[0027] Specifically, the optical receiving unit (ROSA) adopts a coaxial package, and has a semiconductor optical amplifier (SOA), a photodetector, a transimpedance amplifier (TIA), a semiconductor cooler (TEC) and optical elements inside. The input optical signal is first amplified by the semiconductor optical amplifier and then enters the photodetector. The photodetector converts the received optical signal into an electrical signal, and the transimpedance amplifier amplifies the electrical signal and transmits it to the DSP chip. The semiconductor cooler is used to control the temperature of the semiconductor optical amplifier to keep its temperature and performance stable. At the same time, in this process, the SOA control circuit connected to the outside of the optical receiving unit provides a driving current to the semiconductor optical amplifier, so that the semiconductor optical amplifier achieves the optimal amplification gain.
[0028] Specifically, the SOA control circuit includes a DC drive chip (IDAC) and its peripheral circuits. The DC drive chip is connected to the MCU main control unit through an IIC interface. The MCU main control unit monitors the size of the light power received by the optical receiving unit through the received light power sampling circuit to adjust the output current of the DC drive chip, thereby ensuring that the semiconductor optical amplifier operates at the optimal amplification gain under each input light, thereby improving the module sensitivity index, which is beneficial to long-distance signal transmission.
[0029] Specifically, the DSP chip includes a receiving clock recovery circuit, a transmitting clock recovery circuit, a crystal oscillator circuit, a digital core processing circuit, and a signal output circuit. The receiving clock recovery circuit is mainly used to recover the electrical signal output by the internal transimpedance amplifier of the optical receiving unit (ROSA). The digital core processing circuit is responsible for processing the recovered signal and outputting 4×25G NRZ or 2×25G PAM4 electrical signals to the electrical interface circuit through the signal output circuit. In the signal processing stage, the values of the internal registers of the DSP chip can be read and written to adjust the receiving end equalization, SLA (service level agreement) and output amplitude so that the relevant parameters of the signal meet the protocol requirements.
[0030] The transmitting clock recovery circuit recovers the clock of the 4×25G NRZ or 2×25G PAM4 electrical signal input by the electrical interface circuit. After being processed by the digital core processing circuit, the recovered electrical signal is transmitted to the EML control circuit through the signal output circuit. The EML control circuit converts the input signal and drives the EML laser to convert the electrical signal into an optical signal. The external crystal oscillator circuit consists of a 156.25MHz crystal oscillator chip and peripheral circuits to provide an accurate clock frequency for the DSP chip. In the signal processing stage, the values of the internal registers of the DSP chip can be read and written to configure parameters including but not limited to CTLE, OFFSET / SLA, Swing, De-emphasis, and LOOP Bandwidth to optimize the signal quality output to the laser. In addition, the DSP chip can implement LOS indication through hardware pins, and can also output hardware LOL and INTL signals to the MCU to implement functions such as detecting photoelectric signals.
[0031] Specifically, the transmitting optical unit (TOSA) adopts a coaxial package, which contains an EML laser, a semiconductor cooler (TEC) and optical components. The EML laser converts the electrical signal of the EML control circuit into an optical signal. The bias current, modulation amplitude, etc. of the laser can be controlled by an external analog signal. The center value of the wavelength of the optical signal emitted by the EML laser is 1310nm. The semiconductor cooler (TEC) is used to control the temperature of the EML laser to keep the laser temperature and performance stable, and control the wavelength of the EML laser to be stable within ±1nm to meet the transmission standard. The optical component is used to collimate the optical signal output by the EML laser and merge it into the optical fiber.
[0032] Specifically, the TEC driving circuit includes two TEC driving chips, a TOSA temperature sampling circuit and a ROSA temperature sampling circuit. The two TEC driving chips provide driving current for semiconductor refrigerators one and two respectively, so that semiconductor refrigerators one and two are in a heating or cooling state according to changes in ambient temperature. The TOSA temperature sampling circuit is responsible for monitoring the operating temperature of the EML laser inside the optical transmitting unit (TOSA), and the ROSA temperature sampling circuit is responsible for monitoring the operating temperature of the semiconductor optical amplifier inside the optical receiving unit (ROSA).
[0033] Specifically, the slow start unit includes a slow start circuit, which is used to prevent a large impact current from appearing during power on and off to affect the optical module. The slow start time can be modified by adjusting the resistance and capacitance values of the external circuit. The electrical interface provides an input voltage for the slow start circuit, and the input voltage is connected to the power management circuit after the slow start. The power management circuit reduces the input voltage to 0.65V, 1.05V and 1.9V respectively through three DC-DC step-down circuits, of which 0.65V and 1.05V are used to power the DSP chip circuit, and 1.9V is used to power the DSP chip circuit, the EML control circuit and the SOA control circuit.
[0034] Specifically, the MCU main control unit includes an MCU chip and an analog DAC circuit. Since the number of DAC pins cannot meet the design requirements, 3 PWM pins are used to simulate the DAC output to control related functional circuits. The MCU chip is connected to the QSFP28 electrical interface through the IIC interface, and provides relevant digital diagnostic signals to the QSFP28 electrical interface circuit according to the protocol requirements. The DSP chip and the DC-DC internal registers in the power management circuit are read and written by simulating the host IIC. The DC-DC step-down circuit is connected through the I / O port to control the power-on timing of the DSP chip and the laser and the implementation of the LPMODE mode. The EML control circuit is connected through the I / 0 port to control the light emission of the laser. At the same time, the MCU main control unit also realizes the monitoring of TOSA temperature, ROSA temperature, operating voltage, transmitting end optical power, receiving end optical power and TEC current; the TEC drive output current is controlled by the PID algorithm to achieve laser temperature stability.
[0035] Optionally, the DSP chip used is model IN010C25-CA02.
[0036] Optionally, the MCU chip model used is STM32L431RBI3.
[0037] Optionally, the photodetector is a 53G PD detector.
[0038] Optionally, the EML laser is a 53G EML laser.
[0039] Optionally, the electrical interface is a QSFP28 electrical interface.
[0040] Optionally, the light emitting unit and the light receiving unit are connected to the PCB board via an FPC flexible board.
[0041] In summary, this embodiment provides an EML solution optical module with a QSFP28 package, an operating temperature of 0 to 70 degrees, and a transmission rate of 100G, which is applied to scenarios such as 5G mobile bearer and metropolitan area fixed network upgrade. A DSP chip is used to perform clock recovery and compensation on high-speed signals, so that the electrical signal input to the laser and the signal output to the electrical interface meet the transmission requirements specified in the protocol. The optical transmitting unit and the optical receiving unit are coaxially sealed to prevent the internal components from being affected by water vapor, dust, oil and other substances, thereby ensuring the module life and the stability of service transmission and enriching the application environment of the module.
[0042] Those skilled in the art should understand that the present invention can be implemented in many other specific forms without departing from the spirit and scope of the present invention. Based on the embodiments of the present invention, any changes and modifications made by ordinary technicians in the field of the present invention according to the above disclosure are within the scope of protection of the claims.
Claims
1. A single-wavelength 100G long-distance transmission optical module, characterized in that: The optical module includes an MCU main control unit, a DSP chip, a light receiving unit, a light emitting unit, multiple functional circuits and an electrical interface. The DSP chip is respectively connected to the MCU main control unit, the electrical interface, the light receiving unit and the light emitting unit. The MCU main control unit is connected to the electrical interface and the multiple functional circuits. The multiple functional circuits include a TEC drive circuit, an EML control circuit, an SOA control circuit, and an optical power sampling circuit.
2. The single-wavelength 100G long-distance transmission optical module according to claim 1, characterized in that: The optical module also includes a slow start unit and a power management unit, the power management unit includes a plurality of DC-DC step-down circuits, the input end of the slow start unit is connected to the electrical interface, the input end of the power management unit is connected to the output end of the slow start unit, and the output end of the power management unit is connected to the DSP chip and the plurality of functional circuits.
3. The single-wavelength 100G long-distance transmission optical module according to claim 1, characterized in that: The output ends of the SOA control circuit and the optical power sampling circuit are respectively connected to the light receiving unit. The devices in the light receiving unit are coaxially packaged. The light receiving unit includes a semiconductor optical amplifier, a photodetector, a transimpedance amplifier, a semiconductor cooler and an optical element.
4. The single-wavelength 100G long-distance transmission optical module according to claim 3, characterized in that: The SOA control circuit includes a DC drive chip and a peripheral circuit, and the DC drive chip is connected to the MCU main control unit through an IIC interface.
5. The single-wavelength 100G long-distance transmission optical module according to claim 1, characterized in that: The output end of the EML control circuit is connected to the light emitting unit. The components in the light emitting unit are coaxially packaged. The light emitting unit includes an EML laser, a semiconductor refrigerator and an optical element.
6. The single-wavelength 100G long-distance transmission optical module according to claim 1, characterized in that: The output end of the TEC driving circuit is connected to the light emitting unit and the light receiving unit respectively. The TEC driving circuit includes two TEC driving chips, a TOSA temperature sampling circuit and a ROSA temperature sampling circuit.
7. The single-wavelength 100G long-distance transmission optical module according to claim 1, characterized in that: The DSP chip comprises a receiving clock recovery circuit, a transmitting clock recovery circuit, a crystal oscillator circuit, a digital core processing circuit and a signal output circuit.
8. The single-wavelength 100G long-distance transmission optical module according to claim 2, characterized in that: The MCU main control unit includes an MCU chip and an analog DAC circuit, and the MCU chip is connected to the electrical interface via an IIC interface.
9. The single-wavelength 100G long-distance transmission optical module according to claim 8, characterized in that: The MCU chip is connected to the EN pin of the DC-DC chip in the DC-DC buck circuit.
10. The single-wavelength 100G long-distance transmission optical module according to claim 8, characterized in that: The MCU chip is connected to the EN pin of the EML control chip in the EML control circuit.