Spectral broadening and a prospect for pulse compression of Yb:YAG thin-disk laser pulses by nonlinear SHG in a BBO crystal with time predelay and tilting of the pulse fronts

0556011 - FZÚ 2023 RIV US eng J - Journal Article
Duda, Martin - Novák, Ondřej - Cimrman, Martin - Huynh, Jaroslav - Smrž, Martin - Mocek, Tomáš
Spectral broadening and a prospect for pulse compression of Yb:YAG thin-disk laser pulses by nonlinear SHG in a BBO crystal with time predelay and tilting of the pulse fronts.
Optics Continuum. Roč. 1, č. 1 (2022), s. 16-30. ISSN 2770-0208
R&D Projects: GA MŠMT EF15_006/0000674
EU Projects: European Commission(XE) 739573 - HiLASE CoE
Grant - others:OP VVV - HiLASE-CoE(XE) CZ.02.1.01/0.0/0.0/15_006/0000674
Institutional support: RVO:68378271
Keywords : pulse compression * nonlinear optical crystal * Yb:YAG laser * BBO crystals
OECD category: Optics (including laser optics and quantum optics)
Method of publishing: Open access

Pulse compression by second harmonic generation in a type II nonlinear optical crystal controlled by a time predelay of the faster input pulse is not simple to achieve high-average power Yb:YAG lasers with wavelength of 1030 nm. The reason is that the borate nonlinear crystals with their excellent thermal properties do not have the optimal ratio of group velocities of the interacting pulses to achieve efficient pulse compression. We have changed the effective group velocities by tilting the pulse fronts at a diffraction grating and imaging the tilted 1.7 ps pulses into the 6 and 8.5 mm thick BBO crystals. As a result, we have measured significant spectral broadening to 4.5 nm, supporting pulses as short as 100 fs, with an energy conversion efficiency in excess of 20 %. The measured data correspond well with numerical simulations. This research opens a way to extend the range of possible applications of Yb:YAG high-average-power thin-disk lasers into the fs regime.
Permanent Link: http://hdl.handle.net/11104/0330377