CN214626994U - 25G CWDM optical module - Google Patents

Abstract

The utility model discloses a 25G CWDM optical module can improve port density, lower consumption. The utility model discloses a following technical scheme realizes: the optical receiving component adopts a 25G PIN laser, receives an optical signal transmitted in an optical fiber through a built-in PIN photodiode, converts the converted optical current into voltage through a built-in trans-impedance amplifier and amplifies the voltage, external equipment sends an electric signal to a laser driver/CDR (complementary digital) in a circuit chip U2 through an SFP28 electric interface, and the electric signal is modulated by a laser driver/CDR built-in equalizer, a clock data recovery and a DML (digital multiplex) driver and then sent into an optical transmitting component U5; the optical power change of the light emitting component U5 caused by the change of the environmental temperature is automatically compensated, the light emitting component is ensured to send constant laser, the constant laser is modulated into laser with a data modulation signal through a modulated electric signal, and the laser is sent to an output optical fiber.

Description

25G CWDM optical module

Technical Field

The utility model relates to an optical communication field relates to a 25G CWDM optical module of mainly used telecommunications field and data center field.

Background

In the technical field of optical modules, an optical module is composed of an optical transceiver module, a functional circuit, an optical interface and the like, wherein the optical transceiver module comprises a transmitting part (TX) and a receiving part (RX). The optical module is a standard photoelectric converter, a transmitting end of the optical module converts an electric signal into an optical signal, the optical signal is transmitted through an optical fiber, and a receiving end of the optical module converts the optical signal into the electric signal. Optical modules in the field of telecommunications generally have high transmission distances. In a data center, an optical module is mainly used for interconnection between a server and a storage device in the data center, and the optical module used in the data center requires a high transmission rate but a relatively short transmission distance.

With the advent of the 5G era, the demand for optical modules has risen dramatically. At present, a 100Gb/s optical module mainly adopts a QSFP28 packaging form and a 400 Gb/s optical transceiver module packaging form, and due to high implementation difficulty, the packaging form mainly focuses on two major multi-source protocols, namely OSFP and QSFP-DD. For 40G optical modules and 100G optical modules, the price is high, the power consumption is large, and the cost and the energy conservation are not much superior. For the 10G optical module with large usage in the early years, although the price and the power consumption are low, the speed cannot meet the current demand. The defects of the three parts are just made up by adopting a 25G CWDM optical module. In the construction of a 5G network, an optical module serves as an indispensable optical communication device and has the function of realizing the interconversion between an optical signal and an electric signal. Currently, 25G optical modules are widely used for 5G forward base stations. The 25G optical module adopts an SFP28 small packaging structure. Has higher port density and less switches and cables, and relatively low power consumption, and the optimal input/output performance and optical fiber capacity are 2.5 times of the 10G Ethernet performance. Therefore, the method is widely applied to the construction of 5G forward base stations. The 25G optical module adopts an SFP28 packaging type and an LC interface, and is divided into 25GBase-SR, 25GBase-LR, 25GBASE-ER and the like according to different standards. The 25GBase-SR optical module is mainly used for short-distance transmission, can transmit within 100M at most, has a central wavelength of 850nm and is an LC interface. The 25GBase-LR optical module is mainly used for medium-short distance transmission, supports 10KM transmission distance, has the central wavelength of 1310nm and is provided with a double LC interface. The 25GBASE-ER optical module is mainly used for medium and long distance transmission, supports the transmission distance of 40KM, has the central wavelength of 1310nm and is provided with a double LC interface. The 5G BIDI SFP28 single-fiber bidirectional optical module is mainly used for medium-short distance transmission, supports a transmission distance of 10KM, has a central wavelength of 1330/1270nm, integrates full-duplex transceiving and has maximum power consumption less than 1.2W. The 25G CWDM SFP28 single-fiber optical module is mainly used for medium-short distance transmission, supports 10KM transmission distance, and has a center wavelength of 1270-1370 nm. At present, the 25G SFP28 LWDM optical module on the market can realize multi-path signal transmission on one optical fiber, but the cost is lower, so the 25G SFP28 LWDM module tends to become a more flexible and stable solution in a 5G forwarding network. The wavelength interval of the 25G SFP28 LWDM optical module is 4nm, which is much narrower than that of the 25G CWDM optical module, and therefore a large wavelength shift occurs. In general, the operating temperature of the SFP28 LWDM optical module is-40 ℃ to 85 ℃, 1 ℃ may generate a wavelength shift of 1nm, and since the temperature span of the 25G LWDM optical module is 125 ℃, the SFP28 LWDM may generate a wavelength shift of 12.5 nm. In order to ensure the stability of transmission, TEC temperature control is essential for 25G SFP28 LWDM optical module, because it can form current by the movement of charge carriers in conductors, when direct current passes through two different conductor materials, heat absorption or heat release will occur on the contact end, which can make the laser stably operate at a set temperature for a long time, thereby stabilizing the wavelength, so that 25G SFP28 LWDM optical module can ensure stable and accurate data transmission in a severe environment. In the design of the receiver, the SFP 2825G CWDM optical module has large dispersion and risks transmission stability, so a more expensive APD receiver is required to ensure the stability of transmission. The 25G DWDM SFP28 optical module is mainly used for meeting the requirement of 5G forward transmission service, the device adopts an EML + APD scheme, the maximum speed is up to 25.78125Gbps, and the transmission distance can reach up to 10km through a single-mode optical fiber. In 5G network deployment, a direct connection scene generally adopts a 25G optical module, and supports two types, namely single-fiber and double-fiber bidirectional. The center wavelength of the 25G multimode optical module is 850nm, the center wavelength of the 25G multimode optical module is a duplex LC interface, the multimode optical module is multimode, the working temperature is 0-70 ℃, the transmitting optical power is-8.4- +2.4dBm, and the 25G multimode optical module can be transmitted to 100 meters by adopting OM4 multimode optical fibers. The traditional three-layer network consists of an Access layer (Access) at the bottom layer, an Aggregation layer (Aggregation) at the middle layer and a Core layer (Core) at the upper layer, wherein the Access layer provides workstation Access to a local network segment and provides connection for a server; the convergence layer provides connection between the access layers and the core layer; the core layer provides high throughput connections between the aggregation layers while being connected to the backbone network (the core layer may be merged with the aggregation layers). The three-layer topological structure is suitable for data transmission (longitudinal transmission) between the data center and the outside, but is not beneficial to data transmission (transverse transmission) inside the data center, and transmission among hosts needs to pass through a plurality of network devices, so that large delay and even data transmission is blocked.

Disclosure of Invention

The utility model aims to solve the technical problem that a can improve port density, lower consumption and price is provided, and is stable and have cost benefit, carries out optical transmission's 25G CWDM optical module under the 5G network, improves the problem of port density, lower consumption and price.

The above object of the present invention can be achieved by the following technical solutions: a 25G CWDM optical module comprising: the optical fiber receiving module U6 is connected with the receiving optical fiber, the optical transmitting module U5 is connected with the transmitting optical fiber, the MCU microcontroller U1 and the power management chip U3 are connected between the circuit chip U2 and the SFP28 electrical interface U4, and the optical fiber receiving module U6 is characterized in that: the optical receiving component adopts a 25G PIN laser, receives an optical signal transmitted in an optical fiber through a built-in PIN photodiode, converts the converted optical current into voltage through a built-in trans-impedance amplifier (TIA) and amplifies the voltage, external equipment sends an electric signal to a laser driver/CDR in a circuit chip U2 through an SFP28 electric interface, and the electric signal is modulated by a laser driver/CDR built-in equalizer, a clock data recovery and a DML driver and then is sent into an optical transmitting component U5. Meanwhile, the laser driver/CDR provides bias current for the light emitting component U5, and an automatic power control APC circuit in the laser driver/CDR dynamically adjusts the magnitude of the bias current of the light emitting component U5, so that the output optical power change of the light emitting component U5 caused by the change of the environmental temperature or the self-aging is automatically compensated, the light emitting component U5 is ensured to send constant laser, and the light emitting component U5 modulates the constant laser into laser with a data modulation signal through a modulated electric signal and sends the laser into an output optical fiber.

The utility model discloses compare and have following beneficial effect in prior art:

the utility model discloses a connect the light receiving module U6 of receiving optical fiber, connect the light sending module U5 of sending optical fiber, MCU microcontroller U1 and power management chip U3 of connection between circuit chip U2 and SFP28 electrical interface U4 constitute 25G CWDM optical module, the transmission speed of 25G CWDM optical module can reach 25Gb/s, best input/output performance and optical fiber capacity are 2.5 times of 10G ethernet performance. Meanwhile, the transmission rate of 50G can be achieved by using 2 optical fiber channels, and the transmission requirement of a 5G optical network is met. If the 40G optical module is realized by a 10G optical module, 4 10G optical fiber channels are needed for realization. In contrast, 25G CWDM optical modules are very advantageous.

The utility model discloses light receiving component adopts 25G PIN laser instrument, receives the light signal of transmission in the optic fibre through built-in PIN photodiode to the photocurrent that will convert into converts voltage and enlargies through built-in transimpedance amplifier (TIA), and external equipment sends the signal of telecommunication through SFP electrical interface to laser driver/CDR in the circuit chip U2, and the signal of telecommunication passes through send into in the light emitting component U5 after built-in equalizer of laser driver/CDR, clock data recovery and DML driver modulate. With higher port density and fewer switches and cables, and relatively lower power consumption. The 25G CWDM optical module adopts the same SFP28 small packaging structure as the 10G optical module, but the transmission capacity reaches 25G, and compared with the 10G optical module, the port density is improved, and the number of switches and cables is less. For the 40G and 100G optical modules with QSFP package structures, the package size is large, the power consumption is high, and the power consumption of the 25G CWDM optical module with the SFP28 small package structure is much lower.

Drawings

Fig. 1 is a schematic block diagram of the 25G CWDM optical module of the present invention.

Detailed Description

See fig. 1. In an embodiment described below, a 25G CWDM optical module includes: the optical fiber module comprises a light receiving module U6 connected with a receiving optical fiber, a light transmitting module U5 connected with a transmitting optical fiber, an MCU microcontroller U1 and a power management chip U3, wherein the MCU microcontroller U1 and the power management chip U3 are connected between a circuit chip U2 and an SFP28 electrical interface U4, and the power management chip U3 comprises: the optical receiving component adopts a 25G PIN laser, receives an optical signal transmitted in an optical fiber through a built-in PIN photodiode, converts the converted optical current into voltage through a built-in trans-impedance amplifier (TIA) and amplifies the voltage, external equipment sends an electric signal to a laser driver/CDR in a circuit chip U2 through an SFP28 electric interface, and the electric signal is modulated by a laser driver/CDR built-in equalizer, a clock data recovery and a DML driver and then is sent into an optical transmitting component U5. Meanwhile, the laser driver/CDR provides bias current for the light emitting component U5, and an automatic power control APC circuit in the laser driver/CDR dynamically adjusts the magnitude of the bias current of the light emitting component U5, so that the output optical power change of the light emitting component U5 caused by the change of the environmental temperature or the self-aging is automatically compensated, the light emitting component U5 is ensured to send constant laser, and the light emitting component U5 modulates the constant laser into laser with a data modulation signal through a modulated electric signal and sends the laser into an output optical fiber.

Preferably, the circuit chip U2 is selected from GN2152 of SEMTECH corporation.

Preferably, the power management chip U3 is an SGM 2564.

Preferably, the optical transmitter module U5 is a 25G DFB TOSA laser with 6 wavelength bands of 1270nm, 1290nm, 1310nm, 1330nm, 1350nm and 1370 nm.

Preferably, the light receiving component U5 adopts a 25G PIN ROSA laser, and the wavelength is 6 wave bands, which are 1270nm, 1290nm, 1310nm, 1330nm, 1350nm and 1370nm respectively.

Preferably, the microcontroller U1 is an 8051 core single chip microcomputer, and an EFM8LB12F32 microcontroller chip from Silicon Labs company is selected.

The light receiving component U6, the circuit chip U2 and the SFP28 electrical interface U4 form a receiving circuit. A PIN photodiode in the light receiving component U6 receives an optical signal transmitted in an optical fiber and converts the optical signal into photocurrent, then the photocurrent is converted into voltage and amplified by a trans-impedance amplifier (TIA) in the light receiving component U6, the voltage amplified by the TIA is sent into a limiting amplifier/CDR through a high-speed signal line, and the voltage is sent into external equipment through an SFP28 electrical interface after data clock sampling, secondary amplification and buffer processing are carried out by the limiting amplifier/CDR.

An input equalizer is integrated in the limiting amplifier/CDR and is used for compensating the loss between the output of the light receiving component and the input of the circuit chip; the limiting amplifier has a high sensitivity of 14mVp-p, 0.7UI high frequency jitter tolerant CDR retimer, and the CML output driver provides programmable output swing and de-emphasis gain to compensate for channel loss between the SFP28 module and the motherboard.

The circuit chip comprises a limiting amplifier/CDR and a laser driver/CDR, the light receiving component U6 converts light information in a receiving optical fiber into an electric signal and transmits the electric signal to the limiting amplifier/CDR, and the limiting amplifier/CDR performs clock sampling, amplification and other processing on the signal received by the light receiving component U6 and outputs the electric signal to the SFP28 electric interface U4; after the MCU microcontroller U1 realizes the digital diagnosis function and the management and control function of the circuit chip, the electrical signal sent by the SFP28 electrical interface U4 is modulated by the laser driver/CDR, and the electrical signal is converted into an optical signal by the optical sending component U5 and sent to the sending optical fiber. And the power management chip is used for power management of the circuit chip and the MCU.

The MCU microcontroller comprises a high-precision temperature sensor and a high-precision voltage sensor, the temperature sensor is used for monitoring the real-time temperature of the 25G CWDM optical module, operating an extinction ratio lookup table and an APC lookup table, and the voltage sensor is used for monitoring the real-time voltage of the 25G CWDM optical module.

The MCU microcontroller properly reduces the frequency and specification of a central processing unit CPU, and connects an internal Memory, a counter Timer, a USB, an analog-to-digital A/D converter, a Universal Asynchronous Receiver Transmitter (UART), a Programmable Logic Controller (PLC) and a direct Memory with each peripheral with Direct Memory Access (DMA) capability through a group of special buses, the DMA directly transmits data between the Memory and an input/output device, the Programmable Logic Controller (PLC) accesses peripheral interfaces of the peripheral DMA controller, and chip driving circuits of the PLC are integrated on a single chip to form a chip-level computer which is used for different combined control in different application occasions.

And the power management chip is used for power management of the circuit chip and the MCU.

A user programmable input equalizer is integrated in the laser driver/CDR and used for compensating channel loss between the host ASIC and the 25G SFP CWDM optical module, and the reference-free CDR is used for clearing input jitter when the data rate is between 24.3Gbps and 28.1 Gbps. If a lower data rate is required, the CDR can be optionally bypassed, and the DML laser driver drives the light emitting module U5 for external use, with user programmable bias current, modulation current, cross point adjustment, and eye pattern adjustment functions, facilitating optimization of the optical eye pattern quality during commissioning and production of the 25G SFP CWDM optical module.

The light emitting component U5, the circuit chip U2 and the SFP28 electrical interface U4 form a transmitting circuit, the light emitting component U5 adopts a 1270nm, 1290nm, 1310nm, 1330nm, 1350nm or 1370nm distributed feedback laser (DFB), and the maximum characteristic of the light emitting component U5 is that the light emitting component U5 has very good monochromaticity (namely spectral purity), the line width of the light emitting component U can be generally within 1MHz, and the light emitting component U5 has very high Side Mode Suppression Ratio (SMSR), and can reach more than 40-50dB at present.

What has been described above is merely a preferred embodiment of the invention. It should be noted that, for those skilled in the art, variations and modifications can be made without departing from the principle of the present invention, and such variations and modifications should be considered as falling within the scope of the present invention.

Claims (10)

1. A 25G CWDM optical module comprising: the optical fiber receiving module U6 is connected with the receiving optical fiber, the optical transmitting module U5 is connected with the transmitting optical fiber, the MCU microcontroller U1 and the power management chip U3 are connected between the circuit chip U2 and the SFP28 electrical interface U4, and the optical fiber receiving module U6 is characterized in that: the optical receiving component adopts a 25G PIN laser, receives an optical signal transmitted in an optical fiber through a built-in PIN photodiode, converts the converted optical current into voltage through a built-in trans-impedance amplifier TIA and amplifies the voltage, external equipment sends an electric signal to a laser driver in a circuit chip U2 through an SFP28 electric interface, and the electric signal is sent into an optical transmitting component U5 after being modulated by the laser driver/CDR built-in equalizer, clock data recovery and DML driver; meanwhile, the laser driver provides bias current for the light emitting component U5, and dynamically adjusts the bias current of the light emitting component U5 by using an automatic power control APC circuit in the laser driver, so that the output light power change of the light emitting component U5 caused by the change of the environmental temperature or the self aging is automatically compensated, the light emitting component U5 is ensured to send constant laser, and the light emitting component U5 modulates the constant laser into laser with a data modulation signal through a modulated electric signal and sends the laser into an output optical fiber.

2. The 25G CWDM optical module of claim 1, wherein: the optical receiving component U6, the circuit chip U2 and the SFP28 electrical interface U4 form a receiving circuit, a PIN photodiode in the optical receiving component U6 receives an optical signal transmitted in an optical fiber and converts the optical signal into a photocurrent, then the photocurrent is converted into a voltage and amplified by a transimpedance amplifier TIA in the optical receiving component U6, the voltage amplified by the TIA is sent into a limiting amplifier/CDR through a high-speed signal line, and the voltage is sent into external equipment through the SFP28 electrical interface after data clock sampling, secondary amplification and buffer processing are carried out by the limiting amplifier/CDR.

3. The 25G CWDM optical module of claim 1, wherein: an input equalizer is integrated in the limiting amplifier/CDR and is used for compensating the loss between the output of the light receiving component and the input of the circuit chip; the limiting amplifier has a high sensitivity of 14mVp-p, 0.7UI high frequency jitter tolerant CDR retimer, and the CML output driver provides programmable output swing and de-emphasis gain to compensate for channel loss between the SFP28 module and the motherboard.

4. The 25G CWDM optical module of claim 1, wherein: the circuit chip comprises a limiting amplifier/CDR and a laser driver/CDR, the light receiving component U6 converts light information in a receiving optical fiber into an electric signal and transmits the electric signal to the limiting amplifier/CDR, and the limiting amplifier/CDR performs clock sampling and amplification processing on the signal received by the light receiving component U6 and outputs the electric signal to the SFP28 electric interface U4.

5. The 25G CWDM optical module of claim 1, wherein: after the MCU microcontroller U1 realizes the digital diagnosis function and the management and control function of the circuit chip, the electrical signal sent by the SFP28 electrical interface U4 is modulated by the laser driver/CDR, and the electrical signal is converted into an optical signal by the optical sending component U5 and sent to the sending optical fiber.

6. The 25G CWDM optical module of claim 1, wherein: the MCU microcontroller comprises a high-precision temperature sensor and a high-precision voltage sensor, the temperature sensor is used for monitoring the real-time temperature of the 25G CWDM optical module, operating an extinction ratio lookup table and an APC lookup table, and the voltage sensor is used for monitoring the real-time voltage of the 25G CWDM optical module.

7. The 25G CWDM optical module of claim 1, wherein: the MCU microcontroller reduces the frequency and specification of the CPU, and connects the Memory, the counter Timer, the USB, the A/D converter, the UART, the PLC and the direct Memory with each peripheral with DMA capability of direct Memory access through a group of special buses, the DMA directly transmits data between the Memory and the input/output device, the PLC accesses the peripheral interface of the peripheral DMA controller, and integrates the PLC chip driving circuit on a single chip to form a chip-level computer, and different combination control is performed for different application occasions.

8. The 25G CWDM optical module of claim 1, wherein: and the power management chip is used for power management of the circuit chip and the MCU.

9. The 25G CWDM optical module of claim 1, wherein: a user programmable input equalizer is integrated in the laser driver/CDR and used for compensating the channel loss between the host ASIC and the 25G SFP CWDM optical module, and when the data rate is between 24.3Gbps and 28.1Gbps, the reference-free CDR is used for clearing input jitter; if a lower data rate is desired, the CDR is optionally bypassed and the DML laser driver drives an external light emitting assembly U5.

10. The 25G CWDM optical module of claim 1, wherein: the light emitting component U5, the circuit chip U2 and the SFP28 electrical interface U4 form a transmitting circuit, and the light emitting component U5 adopts a distributed feedback laser DFB with the wavelength of 1270nm, 1290nm, 1310nm, 1330nm, 1350nm or 1370 nm.

Images