Research On All-Optical Phase Modulation Based On Semiconductor Optical Amplifier

All-optical phase modulation can realize all various phase changes directly in the optical field without optical-electricity-optical conversion process.Semiconductor optical amplifier(SOA)is one of the important basic devices in all-optical signal processing because of its advantages of low power consumption,easy integration and significant non-linear effect.Therefore,this paper proposes an all-optical phase modulation scheme based on the cross-phase modulation principle of semiconductor optical amplifier.The paper studies this type of all-optical phase modulation theoretical and experimental.The main work is as follows:1.The theory of realizing phase modulation with SOA and the principle of phase measurement are deduced and analyzed,laying a foundation for the experimental study of all-optical phase modulation.2.The basic characteristics of SOA,including gain characteristics,polarization characteristics and coding effect,are experimentally studied.On this basis,cross-gain all-optical wavelength conversion is studied,and the effects of detection power,control power and bias current on extinction ratio,signal-to-noise ratio and conversion efficiency of wavelength conversion are analyzed.3.The experimental system of all-optieal phase modulation is completed,and the experimental scheme of measuring non-linear phase shift by using fiber-optical Fizeau interferometer is proposed.The cross-phase modulation characteristics of SOA are studied eomprehensively,and the expressions of phase shift under different conditions of detecting light,controlling light power and bias current are obtained.Finally,the best combination of three factors(phase modulation point)is given.The linewidth enhalcement factor of SOA are calculated.