Theoretical evaluation on laser cooling of ZBLAN:Er3+ glass with in situ optical temperature sensing

A laser cooling route with in situ optical temperature control based on the anti-Stokes fluorescence from 2H11/2 by exciting at 4S3/2 level was proposed in Er3+ doped ZBLAN glass. The radiative transition probabilities between 4f levels and the nonradiative relaxation probabilities of each lower 4f level in Er3+ doped ZBLAN glass were obtained. Furthermore, the population probabilities of the relevant levels were calculated, the laser cooling capability and temperature sensing performance of Er3+ doped ZBLAN were evaluated via numerical calculations. It was found that practical cooling can be achieved in a certain temperature region, and the Er3+ doped ZBLAN glass exhibits good temperature sensing performance in the temperature region of achieving effective laser cooling.