Carrier-envelope phase-stabilized amplifier system

Abstract

We demonstrate a novel scheme for carrier-envelope (CE) phase stabilization of few-cycle laser pulses from a mode-locked oscillator. Our scheme utilizes a monolithic, collinear geometry which obviates the need for splitting the laser output, where a fraction is used for CE-phase control and the remainder used for experiment. Rather than using a microstructured fiber and frequency-doubling crystal to generate the beating signal needed for CE-phase locking, in our scheme self-phase modulation and difference-frequency generation occur simultaneously in a single periodically poled lithium niobate (PPLN) crystal and are used to generate equivalent signals. Direct phase-locking and recompression of the output is enabled because the PPLN crystal transmits the majority of the incident fundamental relatively unaffected. As a result, the output provides few-cycle pulses with an unprecedented degree of short- and long-term reproducibility of the electric field waveform. These unique features, along with the simplicity of the scheme make it perfectly suitable for use in seeding CE-phase stabilized amplified laser systems. Results from a 3 kHz amplified Ti:sapphire system will be presented that validate our assertions.