Sub-ten Nanosecond Laser Pulse Shaping Using Lithium Niobate Modulators and a Double-pass Tapered Amplifier

A system for producing phase-and amplitude-shaped pulses on a timescale of 150 ps to 10 ns has been developed using fiber-coupled lithium niobate phase and amplitude modulators with high-speed electronics (4 GHz). The pulses are then amplified in a double-pass tapered amplifier. Various pulse shapes have been tested, such as exponential intensity, linear frequency chirp with Gaussian intensity, and arctan-plus-linear frequency chirp with double-Gaussian pulses. We have also realized a scheme for generating arbitrary frequency chirps with a fiber loop and a technique for producing arbitrary line spectra using serrodyne modulation. The residual phase modulation produced by the intensity modulator was investigated. Experiments that may benefit from the new system are discussed, such as chirped Raman transfer and ultracold molecule formation