We study the effects of two-photon absorption on the self-phase modulation (SPM) process in silicon waveguides while including both free-carrier absorption and free-carrier dispersion. An analytical solution is provided in the case in which the density of generated carriers is relatively low; it is useful for estimating spectral bandwidth of pulses at low repetition rates. The free-carrier effects are studied numerically with emphasis on their role on the nonlinear phase shift and spectral broadening. We also consider how the repetition rate of a pulse train affects the SPM process.
© 2007 Optical Society of America
Original Manuscript: March 22, 2007
Revised Manuscript: April 30, 2007
Manuscript Accepted: May 1, 2007
Published: July 5, 2007
Lianghong Yin and Govind P. Agrawal, "Impact of two-photon absorption on self-phase modulation in silicon waveguides," Opt. Lett. 32, 2031-2033 (2007)