Research On40Gbps DP-QPSK Transponder Optical Module

The country’s modernization of information construction and the infrastructure oflight transmission are closely related. The present optical Networks is now in a rapidexpansion, and has the increasing volume and various services, also it is flexible inapplication and is heavily demanded in the future. The developing trend of opticalfiber communication is from low-speed singe channel to high-speed multi channel ofall-optical communication networks. Communication and information industry willhave a fierce competition in the world now and in the future.At present, Core optical transceiver applied by40Gbps DWDM system fibernetwork is the40Gbps RZ-DQPSK(Return to Zero Differential Quadrature Phase ShiftKeying) and the40Gbps NRZ-DPSK(Non-Return-to-Zero Differential Phase ShiftKeying) one. While considering that the future optical network will develop intohigher speed one, many experts and system suppliers prefer the DP-QPSK technologyof applying the Polarization multiplexing transmission and the coherent detectionreceiver. By adopting the DP-QPSK(Dual-Polarization Quadrature Phase Shift Keying)coherent reception and coherent receiving technology, long-distance transmission of40Gbps optical transceiver is achieved.40Gbps DP-QPSK has the features of highspectrum efficiency, high dispersion and big tolerance, which can help enhance theutilization of cable line, as well as enhance the spectrum efficiency for the presentDWDM system.Sponsored by National973Program (2010CB328301), the article makes a deepinvestigation into the40Gbps DP-QPSK optical transceiver. The main contents are asfollows.(1)Study and analyze all kinds of formats of modulation and modulationtechniques, especially on DP-QPSK modulation of40Gbps optical transceiver andcoherent demodulation receiving techniques.(2)Study based on the implement technology that each unit of function devicesreceives photonic integrated circuits; study silica photons processing techniques which have coherent reception functions of high-speed optical signals; study core functioncomponents of digital coherent reception, high speed ADC and high speed DSP chips;study DPS chips which are based on CMOS and with high speed signal processing.(3)Specifically analyze the reception principles of coherent reception, design andanalyze the sending and receiving of modulation. Propose key problems need to besolved in40Gbps DP-QPSK optical transceiver.