Laser and gain parameters at 2.7 μm of Er3+-doped oxyfluoride transparent glass–ceramics

✍ Scribed by V.K. Tikhomirov; J. Méndez-Ramos; V.D. Rodríguez; D. Furniss; A.B. Seddon

• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 178 KB
• Volume: 28
• Category: Article
• ISSN: 0925-3467
• DOI: 10.1016/j.optmat.2005.06.017

✦ Synopsis

The room temperature emission spectrum at about 2.7 lm corresponding to the laser transition 4 I 11/2 ! 4 I 13/2 in Er 3+ -doped nanoscaled transparent oxyfluoride glass-ceramic has been measured and stimulated emission cross-section for the transition has been calculated. The intensity of the transition has been found to be 40 times stronger and lifetime 50 times longer in the glass-ceramics compared to the precursor glass, which we show to be due to a change of frequency of the phonon involved in non-radiative de-excitation of the 4 I 11/2 level from 900 cm À1 in the precursor glass to 240 cm À1 in the ensuing glass-ceramics. The absorption cross-section for the excited state absorption 4 I 13/2 ! 4 I 11/2 has been calculated based on the experimental reciprocal emission spectrum and wavelength dependence of the gain cross-section for the lasing transition 4 I 11/2 ! 4 I 13/2 vs population inversion has been derived. The lasing/optical amplification gain parameters, such as population inversion, pump saturation intensity and product of emission cross-section and fluorescence lifetime have been obtained at the 2.7 lm wavelength. A noteworthy result is that laser action at 2.7 lm is possible in these Er 3+ -doped glassceramics, already not taking into account energy transfer or up-conversion processes, related to the 4 I 13/2 level, which favour the population inversion.