Coherent combining of high brightness tapered amplifiers for efficient non-linear conversion

P. Albrodt (1) , M. T Jamal (2) , A. K Hansen (2) , O. B Jensen (2) , G. Blume (3) , K. Paschke (3) , P. Crump (3) , Patrick Georges (1) , Gaëlle Lucas-Leclin (1)

1 Laboratoire Charles Fabry / Lasers
2 DTU - Danmarks Tekniske Universitet = Technical University of Denmark
3 FBH - Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik

We report on coherent beam combining of three high brightness tapered amplifiers seeded by a single-frequency laser at λ = 976 nm in a simple architecture with efficiently-cooled emitters. The maximal combined power of 12.9 W is achieved at a combining efficiency of > 65 % limited by the intrinsic beam quality of the amplifiers. The coherent combining cleans up the spatial profile, as the power content in the central lobe increases up to 86 %. This high-brightness infrared beam is converted into the visible by second harmonic generation, and results in a high non-linear conversion efficiency of 4.5 %/W and a maximum power over 2 W at 488 nm, limited by thermal effects in the PPLN.

Domaines: Optique [physics.optics]; Optique / photonique

P. Albrodt, M. T Jamal, A. K Hansen, O. B Jensen, G. Blume, et al.. Coherent combining of high brightness tapered amplifiers for efficient non-linear conversion. Optics Express, 2019, 27 (2), pp.928. ⟨10.1364/OE.27.000928⟩. ⟨hal-02332528⟩