Numerical analysis and experimental study of thermal lensing of standard and composite Nd:YVO₄ crystal with temperature dependence of thermal conductivity tensor

Abstract

A numerical analysis and experimental study of the temperature distribution and thermal lensing in six types and sizes of standard and composite Nd:YVO 4 crystals with consideration of the temperature dependence of the thermal conductivity tensor is presented. In the first step to test the model, numerical results at 1064 nm and 1342 nm laser wavelengths are compared with previous experimental results in the literature. In these cases there was good agreement between them in comparison with constant thermal conductivity. In the second step, a diode end pumped Nd:YVO 4 laser is constructed with three types of crystals. Single and double-end diffusion bounded crystals have shown equal efficiencies while standard crystal have lower efficiency. A comparison between theoretical and experimental results is done again and a perfect match between them is observed.

Watt-Level Continuous-Wave Mode-Locked Nd:YVO4 Laser With ReSe2 Saturable Absorber

“…Such obstacles have been overcome deliberately in our experiments. Particularly, the diffusion-bonded YVO4/Nd:YVO4 crystal was employed to suppress thermal lens effect as discussed in [46], with matching the well-designed V-folded resonator. The ReSe2 element was prepared in good quality with low insertion loss of 0.81 dB and high damage threshold beyond 30 MW/cm 2 , while its uniform few-layer structure ensures the moderate saturation intensity and modulation depth to support pure CWML operation.…”

“…The coupling efficiency of lens group is over 90%. The a-cut YVO4/Nd:YVO4 composite crystal (Nd 3+ ~ 0.3 at %) was employed as the gain medium, with minimizing the possible thermal lensing effects [45,46]. The cross section of laser crystal is 3 mm ×3 mm.…”

Growth, thermal and spectral properties, and laser performance of Nd3+:CNAGS crystal

“…The thermal conductivity of Nd:CNAGS is higher than that of Nd:glass (0.83 W m −1 K −1 ), but lower than that of Nd:YAG (14 W m −1 K −1 ) and Nd:YVO 4 (κ x = κ z = 5.1 W m −1 K −1 ), indicating that the crystal is more suitable for low repetition rate laser output. 18,19 Absorption spectrum and J-O calculation…”

High-power operation of double-pass pumped Nd:YVO4 thin disk laser

“…According to Ref. [29], for Nd:YVO 4 , the temperature dependence of the thermal conductivity tensor can be written as follows:…”