We present a theoretical model capable of describing the evolution of pulse parameters when stimulated Raman scattering under continuous-wave pumping is employed for amplifying them inside a silicon waveguide. In our approach, pulse evolution is described analytically by a set of coupled equations derived using a variational formalism. Optical losses resulting from linear absorption or scattering, two-photon absorption, and free-carrier absorption are included by introducing the Rayleigh dissipation function. The influence of gain dispersion originated from a relatively narrow Raman-gain bandwidth is also considered. The role of initial pulse width and chirp is studied extensively because of its practical applications. To ensure the validity of the variational technique, all analytical results are compared with the numerical data obtained with the split-step Fourier algorithm.
© 2008 Optical Society of America
Original Manuscript: September 11, 2008
Revised Manuscript: October 15, 2008
Manuscript Accepted: October 16, 2008
Published: December 10, 2008
Samudra Roy, Shyamal K. Bhadra, and Govind P. Agrawal, "Raman amplification of optical pulses in silicon waveguides: effects of finite gain bandwidth, pulse width, and chirp," J. Opt. Soc. Am. B 26, 17-25 (2009)