Effect of Tm3+ concentration on structure, defect, and spectral properties of Tm: YAP crystals

Thermal simulation, optical and laser performances of a YAP/Tm:YAP/YAP composite crystal operated at 1.94 μm

“…The detailed crystal growth, crystalline quality, and spectroscopy with five different Tm 3+ concentrations (2, 2.5, 3, 4, 7.5 at%) have been reported in our previous work. 20 The corresponding crystalline and spectral information for the 2 at% Tm:YAP crystal are as follows: the FWHM of XRC is 0.008°, absorption cross section is 0.69 × 10 −20 cm 2 @794 nm, level lifetime is 6.06 ms, and laser quality factor is 6.75 × 10 −23 cm s, suggesting high crystalline and optical quality, and excellent spectroscopy properties. The as-grown crystals were annealed at 1200 °C for 20 h under a flowing hydrogen atmosphere in a muffle furnace, and then the section with excellent optical quality was confirmed for a processing test and thermally bonding the samples.…”

High-Power Acoustic-Optical Q-Switched 1.83 µm Tm-Doped Bulk Laser

“…In addition to Nd 3+ -based laser materials, the Tm 3+ -doped gain materials have been tested for 1.8 µm laser generation. In fact, Tm 3+ -doped bulk crystals are broadly used to generate a 1.9~2 µm laser by the transitions from 3 F 4 to 3 H 6 with the advantages of broad emission spectrum and high Stokes efficiency [15][16][17]. As we all know, the gain spectrum is located at 1.9~2 µm for the free-running Tm 3+ -doped lasers due to the re-absorption effect [18].…”