waveform-controlled-mid-IR light
A TW-scale few-cycle infrared source with a controlled waveform, operating at a carrier wavelength of 2.1 µm (under construction). Target parameters: ~10 mJ, ~12 fs @ 10 kHz.
It is based on OPCPA currently pumped by a home-built diode-laser-pumped Nd:YLF laser, consisting of a regenerative amplifier and three linear post-amplifiers. Seeded from the oscillator of FP2, it produces 47-ps, 13-mJ, 1053-nm pulses at a 1-kHz rate. The broadband infrared seed covering 1.5-3.0 µm is generated by difference-frequency mixing between the short and long-wavelength components of the spectrally-broadened output of FP2, ensuring passive CEP stability. After being stretched by a grating pair and a Dazzler it is amplified in three OPA stages of PPLN and LiNbO3 crystals, and compressed in bulk silicon. A surface-THG FROG measures the compressed pulse and provides feedback to the Dazzler. The output pulse energy is currently ~0.7 mJ with a pulse duration of ~15 fs (two optical cycles within FWHM).
A disk-based Yb:YAG regenerative amplifier optically synchronized with the OPA seed provides sub-2-ps 1030-nm pulses with pulse energies up to ~10-20 mJ at repetition rates of 1-10 kHz. An Yb:YAG disk-based multipass amplifier will boost this output to > 50 mJ, allowing upgrade of the OPA output energy to the 10-mJ level. Broader bandwidth and a shorter pulses are expected due to the use of shorter OPA crystals.
In the longer run, we pursue multi-color OPA synthesis of frequencies ranging from 0.7 µm to 3 µm using a combination of Yb:YAG fundamental and second-harmonic pumping for providing two-octave infrared optical waveform synthesis and single-cycle pulses for a range of applications in attosecond science.
contact: X. Gu, Y. Deng
contact: X. Gu, Y. Deng
Further reading:
Parametric amplification of few-cycle carrier envelope phase-stable pulses at 2.1 µm, T. Fuji et al. Opt. Lett. 31, 1103 (2006)
Fig. 1. LWS-1 setup. (© thn)