Investigation of the laser characteristics of Li–Nd–La phosphate glass active elements

A comparative investigation was made of the laser characteristics of 5×50 mm active elements made of Li–Nd–La phosphate glass with an Nd³⁺ ion concentration of 8×10²⁰ cm^–3 and made of Y₃Al₅O₁₂:Nd³⁺ with an Nd³⁺ ion concentration of 1.3×10²⁰ cm^–3. For Li–Nd–La phosphate glass active elements, the threshold pump energy was 1 J and the dynamic efficiency was 1.5 times higher than the maximum efficiency for Y₃Al₅O₁₂:Nd³⁺. This gave a total laser efficiency of ~0.5% for a pump energy of 2 J and higher than 1% for a pump energy of 4 J. An investigation of the dependence of the pulse output energy on the average pump power for an Li–Nd–La phosphate glass active element showed that up to pump powers of ~250 W, the output energy did not change by more than 10%.