The effect of Y3+ doping upon Nd: S-FAP transparent ceramics for effective spectral performance improvement

Abstract

In recent years, neodymium (Nd) doped transparent ceramics have played a great role as laser gain media. The ceramics with anisotropic structures have more advantages in luminescence. The Nd, Y co-doped Sr 5 (PO 4 ) 3 F (Nd, Y: S-FAP) nanoparticles were synthesized by a conventional chemical co-precipitation method. The transparent Nd, Y: S-FAP ceramics with high quality were fabricated by the hot-pressed sintering method. Moreover, the Judd-Ofelt (J-O) theory was adopted to further evaluate the spectral properties. The as-synthesized nanoparticles, whose grain size was about 25 nm, were nearly ellipsoidal. The highest transmittance of the ceramic was 2% Nd: S-FAP, reaching 85% at 1000 nm. The calculated absorption cross-section of the 4 I 9/2 → 4 F 5/2 + 2 H 9/2 transition from the measured absorption spectra was 4.58 × 10 −20 cm 2 . With the increase of the concentration of doped Y 3+ ions, the intensity of the emission peak at 1057 nm increased gradually. Moreover, the calculated stimulated emission cross-section of 4 F 3/2 → 4 I 11/2 transitions was 7.61 × 10 −20 cm 2 , which was greatly improved compared to the current matrix. The research, therefore, showed the great promise of Nd, Y: S-FAP as a solid-state laser.