The Generation Of Advanced Modulation Format And Related All-optical Signal Processing

Advanced modulation formats have been regarded as one of the most potential technology in future fiber-optic communication systems due to its ability of upgrading spectral efficiency and tolerance of dispersion and nonlinearity, while all-optical signal processing is the key technology for future high-speed and large-capacity all-optical switching network. However, the state of arts all-optical signal processing technology mainly focuses on the traditional on-off keying (OOK) modulation format. In this dissertation, some novel generation schemes of advanced modulation format and related all-optical signal processing have been investigated. The main contents are as follows:(1) Based on carrier suppression, a novel 40-Gb/s frequency shift keying (FSK) generation scheme have been proposed and verified by numerical simulation. Transmission performances of the generated FSK signals have also been investigated. Impacts of balanced detection, central frequency detuning and bandwidth of the discrimination filter on the performance of the received signal have been discussed in detail. Moreover, some methods were presented and discussed to optimize the FSK generation scheme. Based on demodulation of return-to-zero-differential phase shift keying (RZ-DPSK) and an optical delay line (ODL), a novel 40-Gb/s phase-incorporated Manchester generation scheme have been proposed and demonstrated experimentally. With more compact spectrum of phase-incorporated Manchester, higher dispersion tolerance can be achieved compared to the traditional ASK-Manchester signal.(2) Based on the carrier suppressed FSK signals, a novel frequency shift keying/ intensity modulation (FSK/IM) orthogonal modulation format have been proposed for optical label switching (OLS) network and verified by simulation, where the 40-Gb/s FSK signal is used as payload and 2.5-Gb/s IM is used as label Impacts of the transmission length and the IM modulation depth on the performance of the received payload and label have been investigated and discussed in detail. Moreover, method to optimize the effective range of IM modulation depth was also presented and discussed. Label swapping of the proposed FSK/IM signal base on gain saturation effect of semiconductor optical amplifier (SOA) have been demonstrated by simulation. Impacts of IM modulation depth, fiber transmission length before label swapping and operation parameters of the SOA on the signal performance after label swapping have also been investigated in detail.(3) Wavelength conversion of orthogonal modulated FSK/IM signal based on the four wave mixing (FWM) effect of SOA,have been studied by simulation. The impacts of central frequency detuning between signal and pump, IM modulation depth and signal to pump power ratio (SPR) have also been investigated. Two distinct SPR ranges were found, where one range can be used to realize FSK/IM transparent wavelength conversion and the other can realize label erasing. Moreover, a novel multi-function packet switching unit base on all-optical wavelength converter has been provided and analyized by simulation. In addition to the transparaent wavelength conversion, the proposed multi-function unit can also provide label updating at the same of wavelength conversion according to different data type of income packets.(4) A novel wavelength division multiplexing-passive optical network (WDM-PON) scheme with 40-Gb/s downlink FSK signal and 2.5-Gb/s uplink IM signal have been proposed and verified by simulation. Impacts of bandwidth of channel, FSK-to-IM conversion and parasitic reflection in bi-directional system on the quality received downlink and uplink signal have been discussed. A scheme with additional 2.5-Gb/s IM downlink broadcast signal has been further investigated and simulated, where the downlink broadcast signals are erased and the uplink signals are re-modulated by a refelective SOA (RSOA) simultaneously. Moreover, a hybrid application scheme with the proposed scheme merged with the wireless access was presented and verified.(5)Based on cross-phase modulate (XPM) effect of gain transparent-SOA (GT-SOA), a novel scheme to optically generate 10-Gb/s orthogonally modulated inverted-RZ/DPSK (IRZ/DPSK) signals have been proposed and verified by simulation. Impacts of central wavelength of DPSK signal, SOA input power and holding light on signal quality of generated IRZ/DPSK have also been studied. Moreover, a WDM-PON scheme that can simultaneously generate multi-channel IRZ/DPSK signals has been proposed and simulated. Base on that, a novel non-local all-optical signal accessing scheme has been proposed, which is useful for transparent multiplexing of the signals in access network.(6)Mechanisms of 2R regeneration base on SOA cross-gain compression (XGC) effect have been theoretically analyzed. The analytical expressions of the transfer function of SOA, and the variance of in-phase and quadrature components of SOA output noise have been presented for the case of whether including gain compressing in SOA model or not. Impacts of SOA input power, physical parameter and input noise bandwidth on noise compressing performance have been investigated. Regeneration of 40-Gb/s PolSK base on SOA XGC effect have been investigated and compared with the theoretical results.(7)Based on SOA XGC effect, regeneration of 10Gb/s polarization shift keying (PolSK) signal,40Gb/s non-return zero DPSK (NRZ-DPSK) signals and 40Gb/s NRZ/RZ-FSK signals have been experimentally studied. Impacts of cascaded optical filter, demodulation of DPSK signal and signal optical signal noise ratio (OSNR) on regeneration performance have been analyzed.