Producing and Diagnosing Chirped Nanosecond Pulses

We report on the production and characterization of phase- and amplitude-modulated pulses generated with the aid of fiber-based electro-optic modulators. Arbitrary frequency chirps are produced using an arbitrary waveform generator to drive a phase modulator within a fiber delay loop which also contains a self-injection-locked 780 nm diode laser [1]. To control the pulse amplitude, the light is then sent through a fiber-based electro-optical amplitude modulator, also driven with an arbitrary waveform generator. The resulting chirped pulses are then amplified using a tapered amplifier system. The frequency chirp, including residual phase modulation from the amplitude modulator, is characterized by heterodyning the output pulse with a fixed-frequency reference laser. Such pulses will be useful in controlling collisions between ultracold Rb atoms. This work is supported by DOE. \newline \newline [1] C.E. Rogers III, et al., J. Opt. Soc. Am. B 24, 1249 (2007).