Effect of two-photon absorption on the amplification of ultrashort optical pulses.

Abstract

The effect of two-photon absorption on the amplification of ultrashort optical pulses is studied theoretically by solving a generalized nonlinear Schrodinger equation. An input pulse can be simultaneously amplified and compressed, although the compression factor is smaller in the presence of two-photon absorption. The amplified pulse evolves toward a chirped soliton that is the solitary-wave solution of the underlying propagation equation. It can split into several chirped solitons whose number, width, and peak power depend on the amplifier parameters