A study of thermal shift of the popular laser line E1 (R1 → Y1) transition for Nd3+-doped YVO4 crystal

Abstract

The thermal-shift of the popular laser line E1(R1→Y1 transition) in Nd3+-doped YVO4 crystal is studied by considering both the static contribution due to lattice thermal expansion and the vibrational contribution caused by electron–phonon interaction. The studies are in terms of the pressure- and temperature-dependence of this spectra line. The results suggest that the static contribution to the thermal-shift in sign is opposite to and in magnitude is about 48% of the vibrational contribution. So the neglect of the static contribution in the previous paper is not suitable. When the static contribution is also included, the obtained electro-phonon coupling coefficient in the vibrational contribution is almost twice that obtained in the previous paper by considering only the vibrational contribution. It appears that for the reasonable explanation of thermal-shift of spectral line in laser crystals (in particular, the “soft” crystals), both the static and vibrational contributions should be taken into account.