Research On Characteristics Of Fiber Grating Soliton Buffer

With the various data increasing rapidly, communication network meets a challenge on capacity. Optical communication provides an effective solution, which makes large-capacity and high-speed possible. As a key technology of All-optical Switching, all-optical buffer technology becomes a focus of current research. Fiber Grating Soliton Buffer is a new field of it. With the feature of various velocities and keeping shape and amplitude, Grating Soliton is crucial to optical communication.Based on the nonlinear coupled-mode equations (NLCMEs) in a uniform fiber Bragg grating (FBG), the existence of slow Grating Soliton (GS) is discussed. By introducing non-relativistic adiabatic and quantum approximation to the NLCMEs in the FBG with hyperbolic tangent apodization, and assuming the soliton as a particle with low velocity and invariant energy, the track equation of soliton is obtained. Numerical simulations of velocity and displacement of reflected soliton, slow soliton and standing soliton are carried out to analyze the controllable velocity characteristic of the GS. The results show that the time delay of 2000ns can occur in an apodized FBG with the length of 50 meters and the corresponding average velocity is 0.1c/n. Finally, numerical calculation of the upper NLCME shows the transmission of soliton in apodized grating. The influences of grating parameters, velocity and displacement the initial input pulse solitons on the time delay are further discussed.By choosing proper parameters of the apodized FBG and the initial soliton pulse, GS with any velocity between 0 and c/n can be achieved, which facilitates the compact soliton-based optical Buffer.