Font Size: a A A

Investigation Of All-optical Signal Processing Techniques Based On Fiber-optical Parametric Amplifiers

Posted on:2017-05-03Degree:DoctorType:Dissertation
Country:ChinaCandidate:Y MengFull Text:PDF
GTID:1318330503958161Subject:Optical Engineering
Abstract/Summary:PDF Full Text Request
Optical signal processing is a key technique for next generation fiber optical transmission with ultra-high speed, ultra-large capacity and ultra-long distance. Although traditional O-E-O technique is quite matured and widely deployed, the current O-E-O signal processing has several disadvantages including complex congifuration, high cost and power consumption, low conversion efficiency, non-transparency to modulation formats and bit-rate, and the bottleneck of the electronic processing speed. Therefore, it cannot satisfy the requirement of future wavelength-division-multiplexing(WDM) optical networks for ultra-high speed optical signal processing. All-optical signal processing has great potentials due to the fast response time of femtoseconds, low power consumption, and its transparency to the bit-rate and modulation formats. The contents of the thesis are focus on the all-optical signal processing technique based on fiber-optical parametric amplifier(FOPA), including wideband and low-noise optical amplification, all-optical phase and amplitude regeneration, wavelength conversion and multicasting of differential phase-shift keying(DPSK) and quadrature phase-shift keying(QPSK) signal, as well as phase insensitive and sensitive parametric all-optical switch. The main research achievements are summarized as follows.1) From the three-wave model for the dual-pump one-mode phase sensitive FOPA(PS-FOPA), we derive an analytical expression of optical signal which represents the phase-sensitive gain and step-like phase transfer function. Furthermore, we put forward a seven-wave model for the dual-pump one-mode PS-FOPA, in order to investigate the effect of high-order four-wave mixing(FWM) components on the signal gain. We find that, with respect to the wavelength spacing of dual pumps, the signal power can be transferred to the high-order FWM sidebands and vice versa, due to the high-order FWM interactions. Consequently, we are able to obtain the maximum signal gain under condition of optimal wavelength spacings of dual pumps. Moreover, under condition of the optimal power and wavelength spacing of dual pumps, gain extinction ratio(GER) roll-over of signal and high-order idlers occurs simultaneously.2) We investigate all-optical DPSK regenerative wavelength multicasting based on our proposed seven-wave model comprehensively. Using the optimal parameters, all-optical DPSK regenerative one-to-nine wavelength multicasting can be realized successfully. Q factor and the optical signal to noise ratio(OSNR) of regenerated DPSK signals of all multicastig channels are improved by more than 1.5dB and 3dB respectively. Furthermore, we investigate the effect of the high-order FWM products on the evolution of pump-to-signal intensity modulation transfer(IMT), and find that high-order FWM products are beneficial for the suppression of pump-to-signal IMT.3) We investigate all-optical QPSK phase regenerative and non-phase-conjugated one-to-three wavelength multicasting based on dual-conjugated-pump degenerate PS-FOPA. Using the optimal relative phase of input signal and optimal power of input pump, the OSNR penalty of phase-regenerated QPSK, multicasting signals Copy1 and Copy2 can be decreased by 0.8dB, 1.3dB, and 1.3dB, respectively.4) We experimentally characterize the static and dynamic responses of the phase-insensitive parametric optical switch(PI-POS), whose extinction ratios(ERs) of static response and dynamic response are 24.5dB and 18.8dB, respectively. Furthermore, ER of 18.97 dB for the static reponse of the phase-sensitive parametric optical switch(PS-POS) is experimentally characterized using a one-path configuration. Meanwhile, ER of 10.84 dB for the dynamic reponse is measured using a two-path configuration. We put forward a numerical model for both the PI-POS and PS-POS, whose simulation results agree well with the experimental results.5) Based on our numerical model for the parametric optical switch(POS) by taking the longitudinal dispersion fluctuations of highly nonlinear fiber(HNLF) into account, we investigate the effect of longitudinal zero-dispersion wavelength(ZDW) fluctuations of HNLF on the PS-POS. We find that, under general conditions, ZDW fluctuations can decrease the ER of the PS-POS, while some specific longitudinal ZDW profile is ideal to further increase the ER. Moreover, the ZDW fluctuations of HNLF can result in a nonreciprocal transmission performance of the PS-POS. Compared with the PI-POS, the PS-POS is more sensitive to the ZDW fluctuations. Meanwhile, amplification of vaccum noise may deteoriate the pump depletion of the POS, and consequently the optimal input pump power is compulsory to achieve the maximum ER of the PS-POS.
Keywords/Search Tags:fiber optical communication, parametric amplifiers, phase-sensitive amplifier, phase matching, all-optical signal processing, advanced modulation format, parametric optical switch
PDF Full Text Request
Related items