Optical Limiting in Nonlinear Fiber Bragg Grating

Nonlinear refraction based optical limiting phenomena is investigated analytically in the transmission mode of a fiber Bragg grating using coupled mode theory. A simple expression for intensity dependent transmittivity has been obtained by incorporating the Kerr effect in nonlinear coupled equations. The transmission is studied as a function of the incident intensity at various incident wavelengths. We have found that the transmittance of the grating gradually increases as a ramp function and becomes constant after a critical intensity when the wavelength of the incident light is tuned above the Bragg wavelength.