Femtosecond optical gating with a traveling-wave amplifier

Publisher Website
Google Scholar
Abstract
A traveling-wave amplifier, pumped by high-power femtosecond pulses, operates as an optical gate, providing a gate window of 100 fs and a gain of greater than 109. This property is applied for femtosecond pulse generation from the cw output of a Kr+ laser. The required signal input level is as small as 1 photon/fs. The temporal properties of the traveling-wave amplifier can be fairly well described by a simple rate-equation system that takes into account gain competition between the signal and amplified spontaneous emission. The gate width is determined by the time mismatch between the transit of the signal through the amplifier and the sweep of the pump beam across the active volume.