RESUMEN
This Letter reports on a high-power, narrow-linewidth deep-UV laser platform built upon a frequency-quintupled, Yb-fiber master-oscillator and power-amplifier system. The source, emitting at a pulse repetition rate of 120 MHz with a linewidth of 90 GHz and beam quality of MX/Y2â¼2.1/1.5, has been stably maintained over two weeks by successively changing positions and temperatures of nonlinear crystals in parallel, while outputting a 0.5-W average power at 213 nm.
RESUMEN
High-order harmonic generation (HHG) is currently utilized for developing compact table-top radiation sources to provide highly coherent extreme ultraviolet (XUV) and soft X-ray pulses; however, the low repetition rate of fundamental lasers, which is typically in the multi-kHz range, restricts the area of application for such HHG-based radiation sources. Here, we demonstrate a novel method for realizing a MHz-repetition-rate coherent XUV light source by utilizing intracavity HHG in a mode-locked oscillator with an Yb:YAG thin disk laser medium and a 100-m-long ring cavity. We have successfully implemented HHG by introducing two different rare gases into two separate foci and picking up each HH beam. Owing to the two different HH beams generated from one cavity, this XUV light source will open a new route to performing a time-resolved measurement with an XUV-pump and XUV-probe scheme at a MHz-repetition rate with a femtosecond resolution.