Status of HiLASE project: High average power pulsed DPSSL systems for research and industry

Abstract

We introduce the Czech national R&D project HiLASE which focuses on strategic development of advanced high-repetition rate, diode pumped solid state laser (DPSSL) systems that may find use in research, high-tech industry and in the future European large-scale facilities such as HiPER and ELI. Within HiLASE we explore two major concepts: thin-disk and cryogenically cooled multislab amplifiers capable of delivering average output powers above 1kW level in picosecond-to-nanosecond pulsed regime. In particular, we have started a programme of technology development to demonstrate the scalability of multislab concept up to the kJ level at repetition rate of 1-10Hz. Diode pumping of solid state laser materials in general improves the stability and efficiency of solid state lasers in comparison to flash-lamp pumped laser sources. The main reason for this improvement is the fact that the rather small bandwidth emission of highly efficient semiconductor laser diodes can be perfectly matched to the absorption band of solid state laser materials. The laser is therefore pumped only with the necessary radiation. The laser materials under consideration for HiLASE show furthermore a small Stokes-shift between the absorption and lasing transitions. The two mentioned facts lead to a much smaller heat deposition in the active laser material in DPSSL in comparison to conventional flash-lamp pumping of active materials. The reduced heat deposition, stability and maturity of laser diodes as well as their over the years reduced prices allow nowadays to consider to work on the development of solid state pulsed laser sources entering and exceeding average power ranges in the order of 1-10kW.