Causes of high-order thermal aberrations and their influence on beam quality in end-pumped Nd:YVO₄ crystals

The causes of high-order aberrations, such as triangular astigmatism and coma, are investigated in end-pumped N d:Y V O ₄ crystals. A high-resolution infrared thermal camera is utilized to obtain the temperature distribution on the end face of N d:Y V O ₄ crystals with high-power pumping. It is demonstrated that errors in optical path adjustment and non-uniform heat dissipation would produce additional high-order aberrations, leading to a deterioration in beam quality. The required operating conditions and tolerance ranges for the precise optical path are provided. The experimental results are consistent with the theoretical analysis.