Tunable repetition rate, compact, carrier-envelope phase stable sub-2-cycle, 1 mJ laser system for high harmonic generation
Year: 2025
Type: preprint
Abstract: The ALPS Facility of ELI ERIC provides few-cycle light pulse sources to the international user community. A key group of beamlines utilizes the 1 mJ, sub-6 fs, 100 kHz fiber-based laser system, HR1, which supports attosecond high harmonic generation applications and time-resolved spectroscopy experiments. While the high repetition rate facilitates statistical analysis, it also puts a high thermal demand on beam delivery and targetry due to the high average power. In this paper, we present a laser system as a solution for the high demand of discrete repetition rates from 10 Hz to 10 kHz, spanning several orders of magnitude below the 100 kHz of the HR1 system. This apparatus, referred to as the HR Alignment system, is integrated into the same HHG beamline in the ELI ALPS facility where the 100 kHz HR1 system can also be operated. It offers tunable repetition rate (10 Hz to 10 kHz), carrier-envelope phase (CEP) stabilization, and delivers sub-6 fs pulses with 1 mJ energy. The system comprises an Yb:KGW frontend, two nonlinear compression stages based on multipass cell technology, and precisely designed chirped mirrors. Detailed characterization reveals excellent energy stability, beam quality, temporal contrast, and CEP stability below 300 mrad, all designed to match the pulse parameters of the HR1 laser. This compact, robust, and turnkey system provides high flux for reaction microscopy experiments based on high harmonic generation (HHG) and serves as a valuable asset for ultrafast research for external users of ELI ALPS.
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4408238652