Structure, defects, and spectroscopic properties of a Yb,Ho,Pr:YAP laser crystal

Structure, defects, and spectroscopic properties of a Yb,Ho,Pr:YAlO3 (Yb,Ho,Pr:YAP) single crystal grown by the Czochralski method were investigated. The effective segregation coefficients of the Yb3+, Ho3+, and Pr3+ ions are 1.06, 1.32, and 0.90 in YAP host, respectively. The structural parameters are obtained by the X-ray Rietveld refinement method. A high crystalline quality of the Yb,Ho,Pr:YAP is determined by the X-ray rocking curve. The dislocations of (100), (010), and (001) faces are studied using the chemical etching with the phosphoric acid etchant. The absorption spectra show that there exists strong absorption in the wavelength range of 900-1000 nm, and the fluorescence spectrum excited by 970 nm LD presents that the strongest emission is located at 2853 nm, indicating the Yb3+ ions can be acted as the sensitizer for the Ho3+ ions. The level lifetimes indicate that the Pr3+ ions can play a deactivator role for the Ho3+ ions. All these results imply that the Yb,Ho,Pr:YAP crystal can be regarded as a promising candidate for realizing 2.8-3.1 μm laser output.