Cancellation of Raman self-frequency shift for compression of optical pulses

摘要

We study how an optical fiber soliton can be manipulated and compressed by interactions with a properly prepared group velocity matched pump wave (waves). The pump wave is scattered at the soliton, which is then accelerated, compressed, and may even reach a nearly single-cycle regime. Unfortunately, the pump wave scattering is efficient only in a narrow frequency window and the scattering process is easily destroyed by the soliton self-frequency shift. The latter inevitably violates the velocity matching condition. We demonstrate numerically that soliton enhancement can be to some extent restored if soliton self-frequency shift is previously canceled by an additional pump wave. Still the available compression degree is considerably smaller than that in the Raman-free nonlinear fibers.