Fabrication and Optical Properties of High‐Performance Polycrystalline Nd:YAG Ceramics for Solid‐State Lasers

TLDR

The authors fabricated transparent polycrystalline Nd:YAG ceramics by solid‑state reaction of >99.99 wt % pure powders and demonstrated continuous‑wave laser oscillation using a diode‑laser excitation system. The ceramics exhibited ~50 µm grains, 99.98 % relative density, a 309 mW oscillation threshold, and 28 % slope efficiency, matching or surpassing the performance of a 0.9 at.% Nd:YAG single crystal.

Abstract

Transparent polycrystalline YAG with nearly the same optical characteristics as those of a single crystal were fabricated by a solid‐state reaction method using high‐purity powders (>99.99 wt% purity). The average grain size and relative density of the 1.1 at.% Nd:YAG ceramics obtained were about 50 μm and 99.98%, respectively. An oscillation experiment was performed on a cw laser by the diode laser excitation system using the fabricated ceramics. The experimental results indicated an oscillation threshold and a slope efficiency of 309 mW and 28%, respectively. These values were equivalent or superior to those of the 0.9 at.% Nd:YAG single crystal fabricated by the Czochralski method.