Applications Of Four-wave Mixing In All-optical Singal Processing

The transmission of the signal is based on the optical fiber in contemporary communication network.The signal processing is still based on the electrics which leads to a high costing and decreases the transmission efficiency.Signal processing in optical domain,based on the technic of all optical signal processing,could make full use of the band resource and fundamentally circumvent of inherent electronic bottleneck of the microelectronic technologies.Hence this technic could make significant difference in the high speed optics communications.The Four-wave Mixing(FWM)is the parametric process.FWM-based all optical signal processing,benefiting from the ultra-short responsive time and the generation of new frequence components,gets the enormous attention and becomes outstanding among other technics.In this thesis,the simulation and calculation in all optical signal processing based on the parametric process,FWM effect,is done in different nonlinear medium.The major contents and the innovating results are listed below:1.The principle of FWM-based all optical sampling is investigated and the scheme of multicast parametric synchronous optical sampling is proposed.120 GSa/s sampling rate of the 10Gb/s Non return to zero on-off keying(NRZ-OOK)signal is obtained,by utilizing a mode-lock laser with the pulse repetition rate of 10 GHz.The proposed scheme could alleviate the requirement of the repetition rate of the mode-lock laser used for getting a high sampling rate.Besides,it could decrease the number of the copies in the similar scheme,then the scheme of all optical sampling could be simplized.2.The FWM-based wavelength conversion in silicon waveguide is investigated.The quasi-phase match is utilized by changing the width of the waveguide,which could directly changes the dispersion parameters of the waveguide.Consequently,the conversion efficiency and the bandwidth obtained in this waveguide are increased.Benefiting from the structure of the proposed waveguide,the problems induced by the nonlinear absorption such as two-photon absorption(TPA),free carrier absorption(FCA)are alleviated.The conversion efficiency and the bandwidth could be further enhanced and the influence of the nonlinear absorptions could be significantly decreased by comparing and optimizing the structures of the silicon waveguides.3.The ultra-short pulse train generation based on the modulation instability(MI),the FWM effect in the time domain,is investigated in the silicon-organic hybrid(SOH)waveguide.In order to achieve the strong MI effect,the SOH waveguide is designed as the slot type and the organic material which owns a high nonlinear refractive index and low nonlinear absorption is utilized to fill in the slot.Simulation results show that the designed SOH waveguide has the potential to be the on-chip ultra-short pulse source by using the low pump power.The research is based on the theory of the FWM effect.The investigation of the FWM effect and the corresponding applications in fiber,silicon waveguide and the SOH waveguide could provide some ideas for the applications of all optical signal processing.The research is expected to be extensively implemented in the fields of the ultra-broadband optical communication networks and high-speed information processing.