Investigation Of Phase Match And Frequency Conversion In Microstructure Fiber

Microstructure fiber(MF) has many excellent properties because of the flexible structure, which are not available in traditional optical fibers such as multiple zero-dispersion wavelengths, dispersion flatted, highly birefringent, highly nonlinear coefficient and so on. Therefore, these characteristics made MF with important application in frequency conversion. Thus, phase match in MF with multiple zero-dispersion wavelengths, four-wave mixing in MF with cladding composed of three large air-holes,Raman soliton self-frequency shift(SSFS) in a highly birefringent microstructure fiber are the research direction. The main contents are described as follows:First, theoretical fundamentals including the method of studying the MF and the calculation formula of each characteristic are introduced.Second, phase mismatch in MF with multiple zero-dispersion wavelengths are investigated. MF with three and four zero-dispersion wavelengths are studied and designed by multi-pole method. Phase match are numerical simulated when the pump varies from the normal dispersion regime around the first zero-dispersion wavelength to the last zero-dispersion wavelength.Third, MF whose cladding is composed of three air-holes is designed. Its mode characteristics, dispersion and phase match are investigated by full vector finite element method. Four-wave mixing and frequency conversion experiments are carried out in a home made MF when pumping by Ti-sapphire fs laser pulse with central wavelength at850 nm, the experimental phenomena is explained reasonably.Fourth, the Raman SSFS in MF under different experimental conditions is studied.Numerical simulation shows that the various characteristic parameters in each fundamental orthogonal polarization mode by full vector finite element method. Then, by changing the polarization state of the pump, the pump power and the pump wavelength and fiber length these factors of Raman SSFS effect are studied.