Modulation Instability In A Photonic Crystal Fiber

Photonic crystal fiber, is a new class of optical fiber which is made by single material with an ordered array of microscopic air holes running along its length. Photonic crystal fiber has remarkable optical properties that can not be obtained using conventional fiber. It is currently the intense research.In this paper, The nonlinear Schrodinger equation of the propagation of a light pulse in a photonic crystal fiber has been utilized. We studied the scalar modulation instability and the vector modulation instability in the photonic crystal fiber and giving the gain spectrum. Modulation instability in a photonic crystal fiber has been studied not only in anomalous dispersion regime but also in normal dispersion region. We discovered that modulation instability can occur in both region because of the existence of the fourth-order of dispersion. And the third-order of dispersion has nothing for the modulation instability. The results show that the different input pulses and nonlinear coefficient have different gain spectra obviously.