HiLASE-I-15
Highly efficient frequency conversion scalable from 10 J at 10 Hz to 100 J 10 Hz using DPSSL laser technology
J. Phillips1, S. Banerjee1, P. Mason1, K. Ertel1, M. Divoky2, J. Pilar2, A. Lucianetti2, M. De Vido1, T. Butcher1, Ch. Edwards1
1STFC, Central Laser Facility, Chilton, Didcot, United Kingdom
2HiLASE Centre, Institute of Physics of the Czech Academy of Sciences, Dolní Brezany, Czech Republic
High energy (100 J- level) and high average power (1kW) nanosecond diode pumped solid-state laser (DPSSL) systems operating at near-IR, are required for new scientific applications like material processing, advanced imaging and high energy density (HED) experiments. To increase the functionality of these near-IR DPSSL systems, efficient and stable frequency conversion to visible light is a pivotal step towards development of ultra-short (fs) amplifier via OPCPA or Ti:Sapphire pumping. Recently, we have successfully demonstrated a 100J-scale (beam size 75 mm square) DPSSL based on cryogenic gas cooled, multi-slab ceramic Yb:YAG amplifier technology. DiPOLElOO / "BiVOJ" has been operated at 10 Hz with pulse energy of 105 J and pulse duration of 10 ns with an optical-to-optical conversion efficiency of 22.5%1. Owing to the limited availability of large aperture non-linear optical crystals2, we have used a scaled-down approach with the 10J and 100J outputs, respectively. The 100J output beam is 75 mm square and we reduce this beam to 50 mm square. For the 10 J output we reduce the beam from 22 mm to 14 mm square. We also present the design of 10 J and 100 J frequency conversion stages where the 10 J has been implemented on the "Bivoj" laser at HiLASE as part of the "HiLASE Centre of Excellence" Widespread Teaming project, where it will be used for experiments including damage testing of optics and laser shock peening We describe frequency conversation for second harmonic from the fundamental for 60% conversion efficiency at 5.6J input. We also show results for frequency conversation to third harmonic at 60% conversion efficiency for the same input. The second harmonic RMS is 0.84% at 3.58 J at SHG with 60% efficiency for 1.8 hours measured at HiLASE. We also describe at setup for 100 J for frequency conversion at CLF using the DiPOLE100.
The authors gratefully acknowledge funding for this work from the H2020 Widespread Teaming action and the Czech Ministry of Science.
References
[1] P. Mason, M. Divoky, K. Ertel, J. Pillar, T. Butcher, M. Hanus, S. Banerjee, J. Phillips, J. Smith, Mariastefania De Vido, A. Lucianetti, C. Hernandez-Gomez, T. Mocek and J. Collier Optica Vol 4, No. 4, 438 (2017).
[2] J. P Phillips, S. Banerjee, M. Fitton, T. Davenne, J. Smith, K. Ertel, P. Mason, T. Butcher, Mariastefania, J. Greenhaulgh, C. Edwards, C. Hernandez-Gomez and J. Collier, Optics Express, 24, 19682, (2016).