Study of Anti-Stokes Luminescence of ZBLAN:Нo3+ Ceramics Excited at 1908 nm

• Published in: Optics and spectroscopy Vol. 125; no. 4; pp. 487 - 491
• Main Authors: Savikin, A. P., Perunin, I. Yu, Kurashkin, S. V., Budruev, A. V., Grishin, I. A.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 2018; Springer Nature B.V
• Subjects: Ceramics; Excitation; Lasers; Luminescence; Mathematical models; Optical Devices; Optics; Photonics; Physics; Physics and Astronomy; Populations; Spectroscopy of Condensed States; Visualization; anti-Stokes Luminescence; Exciting Radiation Intensity; Holmium Ions; Obtained Time Dependences; Phonon Matrix
• ISSN: 0030-400X; 1562-6911
• DOI: 10.1134/S0030400X18100211

Visualization of IR radiation of a Tm:YLF laser with a wavelength of 1908 nm in 53ZrF 4 –20BaF 2 –3LaF 3 –1HoF 3 –3AlF 3 –20NaF (mol %) ceramic samples is studied. The luminescence spectra of Но 3+ -doped ZBLAN ceramics exhibit bands in the regions of 540, 650, and 900 nm, which correspond to the 5 S 2  →  5 I 8 , 5 F 5 → 5 I 8 , and 5 I 5 → 5 I 8 transitions, the red band (650 nm) being most intense. The population of the upper levels of these transitions can be explained using the cascade excitation mechanism. A visualization model is developed based on balance equations for populations of the upper energy states of Но 3+ ions. The population distributions are numerically estimated as functions of the excitation intensity. The obtained time dependences of the populations of the 5 S 2 and 5 F 5 states correlate with the experimental time dependences of the luminescence intensity at the 5 S 2 → 5 I 8 and 5 F 5 → 5 I 8 transitions upon pulsed excitation. The threshold power density of a Tm:YLF laser at which luminescence of the ceramic samples was observed was ~2 W/cm 2 .