Fiber Bragg Grating Based Intensity Dependent Optical Notch Filter
Santosh Pawar, Shubhada Kumbhaj, Pratima Sen and Pranay Kumar Sen
We have reported the results of an analytical study of nonlinear reflection characteristics of uniform fiber Bragg grating at high excitation intensity. The nonlinear coupled mode equations have been solved analytically to obtain the reflectivity of the grating in the nonlinear regime. The complete analysis is made considering the propagation of a CW laser beam at high input intensity. The study revels that the stop band at the Bragg wavelength shifts towards higher wavelength side with increasing excitation intensity and splits into two equally intense bands at a specific input intensity. These intensity dependent features of Bragg grating can be used in the design of optical notch filter with huge potentiality in the current photonic technology.
Keywords: Fiber Bragg grating, self phase modulation, optical notch filter, modulation instability, nonlinear refraction.