New highly efficient LGS-KhM erbium-doped glass for uncooled miniature lasers with a high pulse repetition rate

An investigation was made of several relationships governing excitation transfer in Cr — Yb— Er phosphate glasses. The activator concentrations were optimised. A new LGS-KhM erbium-doped laser glass and its modifications characterised by a low thermal expansion coefficient, an enhanced thermomechanical strength, and a high chemical stability were developed. Under free-running conditions the differential efficiency was 2.6% at the threshold pump energy of 5 J reached in active elements 2.5 mm in diameter and 35 mm long. Under Q-switching conditions a pulse of 30 ns duration and of 10 mJ energy was emitted when the pump energy was 6 — 7 J.