Soliton dynamics in nonuniform fiber Bragg gratings

The dynamics of optical pulses in nonuniform fiber gratings is studied analytically and numerically. Our approach is based on the inhomogeneous nonlinear Schrodinger equation, derived from the nonlinear coupled-mode equations. The problem is analyzed in the context of an adiabatic soliton compressor. The dependences of the soliton amplitude and width on the propagation distance are found. We also show the presence of the phase modulation during propagation. The possibility of optimizing the fiber-grating compressor by choice of a proper length to minimize the phase modulation is suggested. Comparison of analytical results with numerical simulations shows qualitatively good agreement. (C) 2001 Optical Society of America.