Temperature distribution measurement inside an Er:Yb:Lu2Si2O7 crystal under 1.55 μm laser operation

• Published in: Optics and laser technology 2022-11, Vol.155, p.108435, Article 108435
• Main Authors: Chen, Qijun, Huang, Jianhua, Huang, Yidong, Lin, Fulin, Lin, Yanfu, Gong, Xinghong, Luo, Zundu, Chen, Yujin
• Format: Article
• Language: English
• Subjects: 1.55 μm laser; Er:Yb:Lu2Si2O7 crystal; Fluorescence intensity ratio technique; Temperature distribution measurement; Up-conversion fluorescence
• ISSN: 0030-3992; 1879-2545
• DOI: 10.1016/j.optlastec.2022.108435

•Temperature measurement inside the laser crystal was performed based on the fluorescence intensity ratio technique.•Polarized up-conversion fluorescence spectra in 500–580 nm of an Er:Yb:Lu2Si2O7 crystal were measured at 300–680 K.•Temperature distribution inside an Er:Yb:Lu2Si2O7 crystal was measured in real time when a 1.55 μm laser was operating.•The experimental result was compared with the theoretical temperature distribution inside the crystal. Based on the fluorescence intensity ratio technique, the temperature distribution inside an Er:Yb:Lu2Si2O7 crystal was measured in real time when a 1.55 μm laser was operating. The polarized green up-conversion fluorescence in 500–580 nm of the crystal generated simultaneously under laser operation was used as the temperature probe. At a pump beam waist diameter of 400 μm, the highest temperature inside the crystal reached 507 K when the incident pump power and output mirror transmission were 11.13 W and 1.3%, respectively. The experimental result was compared with the theoretical temperature distribution inside the crystal simulated by the finite element analysis method, and the difference between them was analyzed.