Stimulated emission and light amplification in Ho~(3+) doped oxyfluoride glasses and glass-ceramics

摘要

Stimulated emission and light amplification have been observed in Ho~(3+)-doped transparent oxyfluoride glasses and glass-ceramics. A pump and probe experiment has been designed to show this result. A doubled-frequency Nd-YAG pulsed laser oscillating at 532nm was used as the pump source to strongly populate the Ho~(3+) ~5S_2:~5F_4 level. Low power laser radiation at 750nm was used as the probe beam to stimulate the Ho~(3+) ~5S_2:~5F_4 → ~5I_7 electronic transition at the same wavelength. The high power pump pulses provide population inversion between the Ho~(3+) ~5S_2:~5F_4 and ~5I_7 electronic levels and a net positive gain in the 750nm signal is observed both in the precursor glass and in the glass-ceramic. The highest optical gain was obtained for the glass-ceramic sample and corresponds to about 3.7cm~(-1) (～16dB/cm). The dynamics of the gain is also investigated.