Study on luminescent properties of Yb3+-doped phosphosilicate microsphere

Abstract

Cooperative luminescence, down-conversion laser oscillation and cascaded Raman laser in Yb3+-doped 55.93P2O5-3.57Al2O3-15Na2CO3-20SiO2 phosphosilicate glass are studied in the biconical fiber-microsphere coupling system in this paper. A single-mode semiconducter laser with the center wavelength at 976 nm and line-width 0.15 nm is used as a pump source. The blue-shifted cooperative luminescence centered at 476.1 nm is obtained in the Yb3+-doped phosphosilicate microsphere. And a suitable model may be applied to explain the reason for the 11.9 nm blue-shift in this process. Meanwhile, the single-mode laser (at 1058.26 nm) and multimode laser oscillations (from 1060.02 to 1126.08 nm) have also been obtained as the result of resonant oscillation in microsphere cavity. In addition, for the first time so far as we know a self-stimulated cascaded Raman laser is observed in the same phosphosilicate microsphere, which is generated by the down-conversion laser of Yb3+. When the pump power is 8.53 mW, a two-order cascade Raman laser is generated, which extends the laser wavelength to near 1300 nm.