Long-term carrier-envelope-phase-stable few-cycle pulses by use of the feed-forward method

Abstract

The feed-forward technique has recently revolutionized carrier-envelope phase (CEP) stabilization, enabling unprecedented values of residual phase jitter. Nevertheless, its demonstrations have hitherto remained in a proof-of-principle state. Here we show that pulse quality and power issues can be solved, leading to few-cycle pulses with good beam quality. Making use of stable interferometers, we achieve day-long CEP-stable operation of the setup. Out-of-loop RMS phase noise amounts to less than 30 mrad in 20 s, with more than 24 h of CEP-locked operation being demonstrated.

Complete characterization of single-cycle double ionization of argon from the nonsequential to the sequential ionization regime

“…The CEP of the laser is stabilized using the feed-forward technique [31], controlled by varying the dispersion in the CPA stage, and measured using an f-2f interferometer. The laser pulse energy is adjusted with a motorized neutral density filter wheel and the beam is sent into a reaction microscope (REMI) [15].…”

Phase-stable, multi-µJ femtosecond pulses from a repetition-rate tunable Ti:Sa-oscillator-seeded Yb-fiber amplifier

“…To minimize additional intensity and phase noise, the pulse picker is operated in synchronicity with the repetition rate as described in [19]. After phase stabilization by an acousto-optic frequency shifter (AOFS) operated in the feed-forward stabilization scheme [5], the subsequent amplification stages and the compression comprise two Yb-large-pitch-fiber (LPF) amplifiers [23], two grating compressors and a rod-type large-modearea (LMA) fiber for spectral broadening, followed by a chirped-mirror compressor.…”

“…Important contributions to the success of these oscillators are their large optical bandwidth, leading to the direct generation of few-cycle pulses, and the excellent phase stability achievable with feed-back [4] and feed-forward stabilization schemes [5]. However, a major drawback of Ti:Sa amplifiers is the high thermal absorption and thermal lensing in the gain medium, which restricts the average powers to a few tens of Watts even with cryogenic cooling [6], thus limiting high-pulse-energy operation to repetition rates significantly lower than 1 MHz.…”

Dual, feed-forward + feed-back laser frequency control for efficient and convenient diode laser line narrowing

“…The setup used an acousto-optic frequency shifter (AOFS) as feed-forward optical frequency actuator, as in [2,3]. The same could be implemented for locking to a frequency discriminator, however, not only does this lead to a relatively complex and expensive setup, but the bandwidth of the feed forward is limited, to below 1 MHz, by the time delay inherent to the AOFS.…”