Structural disordered orthophosphate crystal Nd³⁺:YBa₃(PO₄)₃ with cubic symmetry

A novel laser crystal Nd³⁺-doped yttrium barium phosphate (Nd:YBa₃(PO₄)₃, hereafter Nd:YBP) with disordered crystal structure was reported. Single crystal growth, thermal, spectral and laser performances were investigated. The thermal conductivity at room temperature was found to be 1.35 W·m⁻¹·K⁻¹ and shown an increased tendency with increased temperature. The spontaneous transition probabilities, radiation lifetime and other parameters were evaluated by using the Judd-Ofelt (J-O) theory. The maximum absorption and emission cross sections for Nd:YBP crystal were obtained to be ∼ 2.32 × 10⁻²⁰ cm² (@ 804 nm) and 6.72 × 10⁻²⁰ cm² (@ 1056 nm), respectively. The measured fluorescence lifetime for Nd:YBP crystal was equal to 351 μs. Furthermore, diode-pumped continuous-wave laser operation was firstly realized near 1060 nm. The slope efficiency was found to be approximately 22% and the maximum output power for Nd:YBP crystal was 256 mW. Results reveal that the disordered crystal Nd:YBP might be further optimized for uses in laser field.