Enhanced light emission near 2.7 μm from Er-Nd co-doped germanate glass

Laser glass gain medium that can convert low cost 808 nm diode laser into 2.7 μm has attracted considerable interest due to its potential application for medical surgery fiber laser system. In this study, enhanced 2.7 μm emission has been achieved in Er3+:germanate glass by co-doping with Nd3+ions under the excitation of an 808 nm diode laser. In the co-doped sample, the experimental results show that the harmful visible emissions via up-conversion were effectively restricted. The reduction of 1.5 μm emission was also detected in the co-doped sample, which indicates significant de-excitation of4I13/2Er3+ion through energy transfer and non-radiative decay in Nd3+ions. In conclusion, the 2.7 μm emission enhancement achieved was due to the increased optical absorption of 808 nm, efficient energy transfer (ET) with efficiency of 81.73% between Er3+and Nd3+ions, and shortening the lifetime of the lower lasing level4I13/2Er3+in the co-doped sample. Therefore, Er3+/Nd3+co-doped germanate glass could be used to fabricate fiber optical gain media for 2.7 μm laser generation.