Tunable and enhanced near-infrared luminescence in Nd3+ doped asymmetrical (CaxSr1-x)5(PO4)3F transparent ceramic

The high optical quality Nd 3+ doped asymmetrical (Ca x Sr 1-x ) 5 (PO 4 ) 3 F transparent ceramics were successfully fabricated using the hot-pressing method. The phase composition, in-line optical transmittance, microstructure and fluorescence properties were discussed. The findings revealed that the Ca 2+ and Sr 2+ were dissolved in Sr 5 (PO 4 ) 3 F crystal cell instead of forming a new heterophase structure. The prepared ceramics exhibited an in-line transmittance of 75 % at 1μm and 55 % at 600 nm, demonstrating high transparency rather than translucency. The emission intensity and FWHM of neodymium doped ceramic samples can be significantly enhanced through co-doping with Ca 2+ and Sr 2+ . Furthermore, by adjusting the Ca/Sr ratio, these samples can achieve controllable emission light within the wavelength range between neodymium doped FAP and S-FAP emissions. The fluorescence lifetime was obviously improved compared with Nd: FAP and slightly reduced compared with Nd: S-FAP. Moreover, the fluorescence lifetime trend varies in accordance with the alteration of lattice constant.