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

Abstract

We demonstrate the temperature distribution, optical and laser performances of a YAP/Tm:YAP/YAP composite crystal fabricated by thermal bonding technology. The thermal distribution simulations show that the bonded crystal possesses a higher thermal dissipation efficiency than that of the unbonded one. The wavefront distortion of the bonded YAP/Tm:YAP crystal is close to the unbonded Tm:YAP, indicating a high bonding quality. The optical transmission spectra and absorption loss suggest that the bonding region is a uniform transition and almost without scattering interface. Moreover, compared with the un-bonded Tm:YAP crystal, a maximum average output power of 41.2 W and slope efficiency of 49.5% are achieved on the bonded crystal, which are increased by 28.4% and 21.0%, respectively. Therefore, the 1.94 μm laser performance can be effectively improved by combining pure YAP crystals on the Tm:YAP crystal as end-caps.