Study On Optical Signal Processing Method Based On Spectral Grating

Photon echo is a kind of transient coherence effect.It's nonlinear mapping of the spectrum grating created by the pulses in resonance medium.There is a wide range of its applications in signal generation,signal processing and optical storage.Theoretical study on spectrum grating and photon echo is the foundation of their applications.The advantage of optical method is becoming obvious with growing demand on communication.We can foresee a bright prospect for signal generation and signal processing based on photon echo.In this paper,we studied on the mechanism of spectrum grating and photon echo,and the applications on population inversion gratings and UWB pulses generation.Specifically,the main works of this paper include:1.Study on the characteristics of spectrum grating and photon echo created by interaction between pulses and resonance medium.On the basis of vector matching,the number and the vector relation of echoes created in medium have been got.The Cayley-Klein parameter method was used to solve the optical Bloch equation.It made that the exact moment of echoes has been got.After that,we explain the formation mechanism of each echo.Then,we put focus on the 2PE and 3PE and studied on the characteristics of spectrum grating and intensity of echo created by interaction between pulses and resonance medium.2.Study on the formation and erasure process of transient population grating created by interaction between pulses and resonance medium and measure of grating formation and erasure by rectangular pulses.The transient population grating was created by pulse 1 and pulse 2 in medium,and was erased by pulse 3 and pulse 4.The optimum range of impulse width and the optimum pulse interval were got by analysis of factors affecting the formation and erasure of grating.In addition,A measure of grating formation and erasure by rectangular pulses was proposed.It was compared with the measure of Gaussian pulses.Finally,an experimental device for the formation and erasure of the grating is given.3.A scheme of monocycle and doublet waveform generation using programmable optical photon echo progress.A theoretical model and stimulated results of monocycle and doublet waveform generation was presented.The factors affecting waveform generation were analyzed.The proposed scheme is suitable for the generation of monocycle and doublet waveforms realtimely.