Solitary waves in Parity-time (PT) symmetric Bragg-grating structure and the existence of Optical Rogue Waves

In this work, we have studied the traveling wave solution in a nonlinear Bragg grating structure in which the core of the optical fiber is having Parity-time (PT) symmetric refractive index distribution. We have found bright solitary wave solution below the PT-threshold for forward wave and dark solitary wave solution above the PT-threshold for backward wave. The effects of increasing the traveling wave speed on the spatio-temporal evolutions of the analytical solutions have been shown and the emergence of the Optical Rogue Waves (ORWs) has been explored based on the system parameters.