CW and Q-switched operations of a Tm 3+ :YAP laser at 1892–1994 nm In-band fiber-laser pumped at 1670 nm

• Published in: Laser physics 2022-08, Vol.32 (8), p.85802
• Main Authors: Antipov, O L, Dobrynin, A A, Getmanovskiy, Yu A, Sharkov, V V, Shestakova, I A, Balabanov, S S, Larin, S V
• Format: Article
• Language: English
• ISSN: 1054-660X; 1555-6611
• DOI: 10.1088/1555-6611/ac7ec7

Tm 3+ :YAP lasers in-band fiber-laser pumped at 1670 nm with a linear or L-shaped cavity were studied in CW, actively and passively Q-switched regimes. High-efficiency CW and repetitively-pulsed operations were registered at three spectral regions: 1987–1994 nm, 1935–1941 nm and 1892–1897 nm. The transition between these three spectral regions was achieved by controlling the pump power and the output mirror in a laser cavity. The highest CW output power that was achieved without degrading the beam quality was 12.2 W at the 52% slope efficiency with respect to the incident pump. Acousto-optically Q-switched operation with the average power of 9.8 W at the 20 kHz pulse repetition rate (PRR) and 6 W at 3 kHz PRR was achieved, the pulse energy was scaled up to 2.7 mJ at 0.5 kHz PRR. The passive Q-switch operation at 1935–1938 nm was obtained using a Cr 2+ :ZnSe saturable absorber; the pulse energy reached 150 µ J at the 20 kHz PRR