Few-cycle, carrier - envelope-phase-stable laser pulses from a compact supercontinuum source

We report on a few-cycle, carrier-envelope-phase-stable laser source based on supercontinuum generation driven by an amplified Er: fiber-based system. Laser pulses from an Er: fiber oscillator are amplified, and these amplified pulses generate a stable supercontinuum in a highly nonlinear optical fiber. The short-and long-wavelength tails of this continuum are used in an f-to-2f interferometer to stabilize the carrier-envelope phase (CEP) of the Er: fiber oscillator via an acousto-optic modulator. Compressing the central part of the continuum, we generate a train of CEP-stabilized laser pulses with a central wavelength of 1170 nm, duration of 9.1 fs (similar to 2.3 optical cycles), and repetition rate of 78.4 MHz. Characterizing the CEP stability of our output pulse train with an out-of-loop f-to-2f interferometer, we find a phase jitter of only 157.4 mrad when integrating the radiofrequency spectrum from 5 mHz to 5 MHz. (C) 2019 Optical Society of America