Spectral properties and high-efficiency broadband laser operation of Tm: CaY0.9Gd0.1AlO4 crystal

We report on spectral properties and a high-efficiency broadband laser operation of Tm:CaY0.9Gd0.1AlO4 (Tm: CYGA) crystal. The polarized absorption and emission spectra, gain cross sections and fluorescence lifetime are systematically studied, presenting a broad absorption and emission spectra and thus a smooth gain band. Furthermore, under an absorbed pump power of 4.35 W, a maximum continuous-wave (CW) laser output power of 1.43 W at 1967.8 nm is obtained, corresponding to a slope efficiency of 42.2 %. The beam quality factors (M2) in X-axis and Y-axis are measured to be 1.011 and 1.027, respectively. A tunable Tm:CYGA laser with a tuning range of 284.7 nm from 1837.5 to 2122.2 nm is achieved employing a birefringent filter (BF). The results indicate that the Tm:CYGA crystal is an excellent laser medium for generating high-efficiency broadband CW laser, indicating its potential for ultrashort pulse generation in the 2-mu m spectral range.

Automated summary

We report on the spectral properties and high-efficiency broadband laser operation of a Tm:CaY0.9Gd0.1AlO4 (Tm:CYGA) crystal. The crystal exhibits broad absorption and emission spectra, offering a smooth gain band. A maximum continuous-wave laser output power of 1.43 W at 1967.8 nm, corresponding to a slope efficiency of 42.2%, is achieved with an absorbed pump power of 4.35 W. A tunable Tm:CYGA laser with a tuning range of 284.7 nm from 1837.5 to 2122.2 nm is realized using a birefringent filter (BF). The results demonstrate the potential of the Tm:CYGA crystal for generating high-efficiency broadband CW laser and ultrashort pulses in the 2-μm spectral range.