Efficient laser operations of unprocessed thin plate of Nd:YPO₄ crystal

The laser properties of Nd:YPO₄ crystal were demonstrated for the first time. For a 1.2 at.% doped Nd:YPO₄ crystal, the absorption cross-section at 803 nm, stimulated emission cross-section at 1063 nm, and fluorescence lifetime was measured to be 8.1 × 10^-20 cm², 1.6 × 10^-19 cm², 156 μs, respectively. With an as-grown 0.6 mm thin slice which was unpolished and uncoated, efficient diode-pumped continue-wave (CW) laser operations were realized at 1.06 and 1.3 μm wavebands. The 1063 nm output power reached 2.16 W when the absorbed pump power was 4.07 W, corresponding to an optical-to-optical efficiency of 53%, and a slope efficiency of 56.4%. The 1.3 μm laser output exhibited the simultaneous operations of dual-wavelengths, i.e. 1338 and 1347 nm. The maximum output power was 800 mW at an absorbed pump power of 3.08 W, giving an optical-to-optical efficiency of 26% and a slope efficiency of 28.2%.