Research of SFP56 long range industrial-temperature optical transceiver based on digital signal processing

This paper mainly studies SFP56 optical transceiver, whose signal transmission rate is 50Gbps, transmission distance is 10km, working wavelength is 1310nm, working temperature is -40℃ to 85℃, and the small form-factor pluggables package structure is adopted. The SFP56 LR I-temp optical transceiver is mainly applied to 5G pretransmission networks to realize high-speed conversion between optical signal and electrical signal during optical signal transmission. The design adopts DSP technology, PAM4 encoding and TOSA scheme with built-in laser driver chip. The built-in laser driver chip is used to provide bias current and modulation current for the laser, thus realizing the stable transmission and reception of optical signals up to 53.125Gbps in 10km fiber. Compared with the traditional CDR technology and TOSA external laser driver chip scheme, DSP technology is based on digital signal processing. In addition to realizing clock and data recovery, DSP technology adds finite impulse response processing and multi-stage filtering in functions. Moreover, the scheme of TOSA built-in driver chip reduces the influence of impedance discontinuity and impedance mismatch of high-speed line between optical chip and electrical chip, so that the indicators of the optical module transmitter are better, the bit error rate of the receiving end is more stable, the power consumption is lower, and the reliability is better.