Research On The Properties Of Supercontinuum Generated In Photonic Crystal Fiber With Three Zero-dispersion Wavelengths

Photonic crystal fiber is a new type of optical fiber,it has many advantages,such as controllable dispersion,high nonlinearity,no cut-off single-mode and so on,which can produce supercontinuum.Supercontinuum has very important application value in such as pulse compression,spectroscopy,laser design and so on.As one of the important parameters of supercontinuum,coherence is restricted in many applications,so the situation of coherence is a measure of an important aspect of supercontinuum,which needed to carry on a thorough research on it.In this paper,by using software,the dispersive property of photonic crystal fiber with three zero dispersion wavelength were analyzed numerically and theoretically.We used this photonic crystal fiber to study the generation of the supercontinuum and measured the coherence quality of supercontinuum:Firstly,based on the generalized nonlinear Schrodinger equation,simulating and discussing the evolution of the generated supercontinuum.The propagation in the photonic crystal of input pulse abides by the generalized Schrodinger equation which requires to be solved by the improved split step Fourier method.Later,under different transmission distance?input pulse energy and input pulse width,discussing the evolution of the generated supercontinuum.The results show that:transmission distance?input pulse energy and input pulse width all have an influence on the supercontinuum.Secondly,simulating and discussing how the coherence property of the generated supercontinuum is affected.The noise considered introduced firstly.Later,deriving complex degree of mutual coherence formula and using this formula to decide the quality of coherence property of the generated supercontinuum.Then,based on the noise,simulating and discussing how the coherence property of the generated supercontinuum is affected under different transmission distance?input pulse energy and input pulse width.The results show that:under the same conditions,the coherence property of supercontinuum is different even though the width of obtained supercontinuum is same roughly.