Raman Maksimenka

4-W, 100-kHz, few-cycle mid-infrared source with sub-100-mrad carrier-envelope phase noise

We demonstrate an optical parametric chirped-pulse amplifier delivering 4-cycles (38-fs) pulses centered around 3.1 µm at 100-kHz repetition rate with an average power of 4 W and an undersampled single-shot carrier-envelope phase noise of 81 mrad recorded over 25 min. The amplifier is pumped by a ~1.1 ps, Yb-YAG, thin-disk regenerative amplifier and seeded with a supercontinuum generated in bulk YAG from the same pump pulses. Carrier-envelope phase stability is passively achieved through difference-frequency generation between pump and seed pulses. An additional active stabilization at 10 kHz combining 2f-to-f interferometry and a LiNbO3 acousto-optic programmable dispersive filter achieves a record low phase noise.

Multi-W, 100-kHz, few-cycle mid-infrared source with sub-100-mrad single-shot carrier-envelope phase noise

Extension of High order Harmonics Generation (HHG) towards XUV and up to soft-x-rays relies on the development of driving sources with specific properties: mid-infrared wavelength, few-cycle pulse duration, high peak intensity, carrier-envelope phase stability and control, high energy and/or high-repetition rate. While longer wavelengths of the driving source extend the HHG cutoff energy through the λ2 dependency of the ponderomotive energy, shorter pulses lead to the higher peak intensities enhancing the HHG conversion yield and extending HHG cutoff energy even further. Additionally, few-cycle driving pulses reduce the number of produced attosecond bursts up to, ideally, a single isolated attosecond pulse. In this case, CEP stability and control is paramount for ensuring optimization and shot-to-shot reproducibility of the HHG yield and spectra.

Few-cycle mid-IR OPCPA front-end at 100 kHz with sub-50 mrad CEP-stability

We present an OPCPA front-end delivering mid-IR (3.2 μm) pulses supporting sub-3.5 optical cycles with unprecedented passive CEP stability (44.2 mrad rms over 84 sec).

Broadband ZGP OPA pumped by femtosecond Ho:YAG chirped pulse amplifier

We demonstrate a broadband parametric amplifier at 6 μm driven by a femtosecond 2.1-μm Ho:YAG chirped-pulse amplifier. The scheme offers an all-in-one solution for seeding, pumping and CEP stabilization of few-cycle pulses in ZnGeP2 and similar mid-IR crystals.