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11LS-P-14
LASER SYSTEMS AND MATERIALS
ALT'22
Quasi-CW lasing performance of Yb:YSAG ceramics
V. Zhmykhov1, D. Guryev1, V.S. Tsvetkov1, E. Dobretsova1, S. Kuznetsov1, M. Nikova2, I. Chikulina2, D.
Vakalov2, V. Tarala2 and V.B. Tsvetkov1
1- Prokhorov General Physics Institute of the Russian Academy of Sciences 2-North Caucasus Federal University, Scientific and Laboratory Complex Clean Room, Stavropol, Russia
Vadimzhmykhov56@gmail.com
Optical transparent ceramics have been widely considered as promising substitute for single crystal laser gain media of the next generation [1]. This substitution becomes possible due to their remarkable advantages, such as high doping concentration, low cost [2], high-dopant homogeneity, easy fabrication of large sample, and realizability of multilayer structure [3]. As one of potential candidates for high-power laser materials, Yb:YSAG ceramics have always gained much attention because of the superior physical properties of Yb ions, e.g. the broad absorption and emission bands, long lifetime, low defect density, no excited state absorption or up-conversion loss and wide range of tunability [4-7].
In this work we demonstrate quasi-CW lasing performance of 10 at. % Yb:YSAG ceramics. The ceramic sample had a thickness of 1 mm and no antireflective coatings. We used a cavity with a length of 2 cm formed by two spherical mirrors. Such cavity provided optimal overlap of the pumping and lasing areas. The ceramics were pumped at a wavelength of 938 nm. The size of the pump spot in the active element was approximately 100 pm. Laser operation was obtained with the quasi-CW pump. The laser performance was studied with different output couplers (Fig. 1 (a)). The maximum output power was 1 W at absorbed pump power of 2.4 W. Laser was operating in TEM00 transverse mode. The best slope efficiency was 49.7% with an output mirror transmittance of 14.5%.
1000 1500 2000 2500 Absorbed pump power, mW
Fig. 1. (a) Quasi-CW performance of the Yb:YSAG laser; (b) typical laser emission spectra measured
at absorbed pump power of 2.4 W.
The spectral characteristics of laser radiation were also studied at different output couplers (Fig. 1 (b)). The lasing spectrum depends on the output mirror type insignificantly. Also, to obtain the best result, it is possible to use antire-flection coatings on the sample on both sides. In future investigations we will assess the impact of the composition (in particular the ratio between Al and Sc) on the spectroscopic properties of the Yb3+ and on the overall laser performance of this material, in order to get additional improvements and information.
This work was supported by the Grant of the President of the Russian Federation, grant №MK-72.2022.1.2
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