Stark components of lower-lying manifolds and phonon effects on sharp spectral lines for inter-Stark transitions of Nd3+ in LLGG crystal host

Abstract The inter-Stark components of the 4 I 9/2 and 4 I 11/2 manifolds have been characterized using the fluorescence spectra for the 4 F 3/2 → 4 I 9/2 and 4 F 3/2 → 4 I 11/2 transitions of Nd3+ in LLGG laser crystal at 80 K. The thermal effects on the linewidths, positions, and line shifts of the 933.6 (R1→X5) and 1057.3 (R2→Y3) nm lines within the respective intermanifold transitions of 4 F 3/2 → 4 I 9/2 and 4 F 3/2 → 4 I 11/2 have also been investigated. The linewidths of these transitions are found to increase with increasing temperature. The 933.6 nm line is found to shift towards the shorter wavelength, while the 1057.3 nm has shifted towards the longer wavelength. The experimental results of the temperature-dependent widths and shifts of these sharp spectral lines are explained using the phonon–ion interaction theory, which assumes the Debye model for phonons in crystalline solids.