Temperature-Dependent Stimulated Emission Cross-Section in Nd3+:YLF Crystal

Giorgio Turri; Scott Webster; Michael Bass; Alessandra Toncelli

doi:10.3390/ma14020431

Temperature-Dependent Stimulated Emission Cross-Section in Nd³⁺:YLF Crystal

Materials (Basel). 2021 Jan 16;14(2):431. doi: 10.3390/ma14020431.

Authors

Giorgio Turri¹, Scott Webster², Michael Bass², Alessandra Toncelli^{3

4}

Affiliations

¹ Mathematics and Science Department, Full Sail University, 3300 University Blvd, Winter Park, FL 32792, USA.
² CREOL, The College of Optics and Photonics, University of Central Florida, 4304 Scorpius St., Orlando, FL 32816, USA.
³ Physics Department, University of Pisa, Largo B. Pontecorvo 3, 56127 Pisa, Italy.
⁴ Italian National Research Council (CNR), Institute of Nanoscience (NANO), 56127 Pisa, Italy.

Abstract

Spectroscopic properties of neodymium-doped yttrium lithium fluoride were measured at different temperatures from 35 K to 350 K in specimens with 1 at% Nd³⁺ concentration. The absorption spectrum was measured at room temperature from 400 to 900 nm. The decay dynamics of the ⁴F_3/2 multiplet was investigated by measuring the fluorescence lifetime as a function of the sample temperature, and the radiative decay time was derived by extrapolation to 0 K. The stimulated-emission cross-sections of the transitions from the ⁴F_3/2 to the ⁴I_9/2, ⁴I_11/2, and ⁴I_13/2 levels were obtained from the fluorescence spectrum measured at different temperatures, using the Aull-Jenssen technique. The results show consistency with most results previously published at room temperature, extending them over a broader range of temperatures. A semi-empirical formula for the magnitude of the stimulated-emission cross-section as a function of temperature in the 250 K to 350 K temperature range, is presented for the most intense transitions to the ⁴I_11/2 and ⁴I_13/2 levels.

Keywords: Nd:YLF; absorption; decay dynamics; rare-earth doped crystal; solid-state laser; stimulated-emission cross-section; thermal effects.