The Key Technology Research On Intensity Modulation Direct Detection For Large-capacity Long-reach Photonic Interconnection

With the continuous growing of the Internet,high-speed Internet access is highly preferred,while the cost is also very sensitive.Intensity modulation direct detection with advantage of low-cost becomes a hot research topic for the application of photonic interconnection.However,due to the nonlinear transmission impairment arising in fiber optical transmission,the standard single mode fiber(SSMF)reach is constrained.In this thesis,based on nonlinear compensation algorithm,large-capacity long-reach intensity modulation direct detection system is comprehensively investigated.In particular,the transmission impairments,especially the nonlinear effect due to the high launched power,is proposed to be compensated by the Volterra model.The main research outcomes of the thesis include:(1)The cost and power consumption are key considerations for photonic interconnection,besides the transmission performance.We first discuss various advanced modulation formats and advanced digital signal processing(DSP)techniques for large capacity long reach photonic interconnection.In addition,we investigate the source of transmission impairment and corresponding digital equalization techniques.(2)We experimentally demonstrate C-band 2 × 56-Gb/s four-level pulse amplitude modulation(PAM4)signal transmission over 100-km SSMF using 18-GHz directlymodulated lasers(DMLs)and direct detection,without inline optical amplifier.A comb filter at the transmitter side is used to realize vestigial sideband modulation,which can improve dispersion tolerance,and a Volterra model based equalizer at the receiver side is used to mitigate the nonlinear distortions.(3)We propose a long-reach passive optical network(LR-PON)based on PAM4 transmission,and experimentally demonstrate downstream transmission over 80-km SSMF.Four 10G-class DMLs at C-band are used for achieving 4×28-Gb/s downstream transmission,and dispersion compensation fiber(DCF)is equipped at optical line terminal(OLT),without using any optical amplifier in optical distributed network(ODN).Meanwhile,sparse Volterra model based equalizer is proposed to mitigate the transmission impairments with substantial 60% reduction of computation complexity.Finally,we can successfully provide a power budget of 33 dB per wavelength channel,indicating of 64 optical network units(ONUs)with more than 1.25 Gbps per ONU.