Author(s)

Bo Li^*, JianSheng Zhang

Affiliation(s)

Department of Physics, School of Basic Sciences, Xi' an Technological University, Xi' an 710021, Shaanxi, China.

Corresponding Author

Bo Li

ABSTRACT

This paper systematically investigates the thermal effects in a laser diode (LD) end-pumped Pr3⁺: YLF green laser. Through numerical simulation, the evolution of the internal temperature field under different pump powers (4-20 W) was analyzed. The results reveal that the heat source and temperature exhibit an exponential decay along the crystal axis, with a persistent hot spot at the pump end-face. Increasing the pump power significantly expands the high-temperature region and intensifies the spatial temperature gradient, leading to severe thermal lensing. Furthermore, the dependence of the thermal lens focal length on key parameters was quantified. The focal length decreases nonlinearly with increasing pump power and decreasing pump spot radius, while a larger crystal diameter alleviates the effect by improving heat dissipation. These findings provide critical insights for the thermal management and resonator design of high-power visible lasers.

KEYWORDS

Pr3⁺: YLF laser; End-pumping; Thermal effect; Temperature field; Thermal lensing effect

CITE THIS PAPER

Bo Li, JianSheng Zhang. Thermal effects in a LD-end-pumped Pr3⁺: YLF green laser. World Journal of Mathematics and Physics. 2025, 3(1): 59-67. DOI: https://doi.org/10.61784/wjmp3018.

REFERENCES

[1] Wang P, Yuan Q, Xia R, et al. Thermal effect analysis on cuboid Pr: YLF crystals pumped by blue laser diodes. Applied Optics, 2023, 62(18): 4797-4804. 

[2] Huang L, Xu X, Zhang N, et al. Recent advances for diode-pumped CW Pr:YLF lasers in visible region (Review). Optics and Laser Technology, 2024, 142, 105578. DOI: https://doi.org/10.1016/j.infrared.2024.105578.

[3] Lin X, Feng Q, Zhu Y, et al. Diode-pumped wavelength-switchable visible Pr3⁺: YLF laser around 670 nm. Opto-Electronic Advances, 2021, 4(4): 210006. DOI: 10.29026/oea.2021.210006.

[4] Tanaka H, Fujita S, Kannari F. High-power visibly emitting Pr3+: YLF laser end pumped by single-emitter or fiber-coupled GaN blue laser diodes. Applied optics, 2018, 57(21): 5923-5928.

[5] Zhang L L. Research progress of blue LD-pumped rare-earth-doped visible fiber lasers. Chinese Journal of Lasers, 2022, 59(15): 1516016.

[6] El-Agmy R M, Al-Hosiny N. Thermal analysis and experimental study of end-pumped Nd: YLF laser at 1053 nm. Optical Engineering, 2017, 56(9): 096104.

[7] Chenais S, Druon F, Forget S, et al. On thermal effects in solid-state lasers: The case of ytterbium-doped materials. Progress in Quantum Electronics, 2006, 30(4): 89-153.

[8] Chen S, Wang L M, Qiu H R. Thermal effect modeling and optimization of Pr3⁺: YLF crystal under high-power pumping. Laser & Optoelectronics Progress, 2023, 60(9): 091001.

[9] Bruneau D, Delmonte S, Pelon J. Pump-to-mode size ratio dependence of thermal loading in diode-end-pumped solid-state lasers. Journal of Physics D: Applied Physics, 2007, 40(22): 6930-6938.

[10] Hardman P J, Pollnau M, Clarkson W A, et al. Thermal lensing in high-power end-pumped Nd:YLF lasers. IEEE Journal of Quantum Electronics, 1997, 33(4): 599-606.

[11] Peng X, Xu L, Asundi A. High-power efficient continuous-wave TEM_oo intracavity frequency-doubled diode-pumped Nd: YLF laser. Applied Optics, 2005, 44(5): 800-807.

[12] Liu Q, Wang L, Zhao C. Analysis of temperature field and thermal lens coupling characteristics in LD end-pumped solid-state lasers. Acta Photonica Sinica, 2024, 53(6): 0620001.

[13] Ma S, Xiong Z, Liu Z, et al. Thermal effects and their suppression of end-pumped gradient-doped Nd:YAG crystals. Infrared Physics & Technology, 2025, 148, 105845. DOI: https://doi.org/10.1016/j.infrared.2025.105845.

[14] Mironov E A, Kuznetsov I I, Palashov, O V, et al. Broadband amplification and thermal lensing in a Yb:YLF crystal in thin and thick geometries. Applied Optics, 2024, 63(14): 4508-4514.

[15] Wang J Y, Pu S S, Wang X H, et al. 1.01-W narrow-linewidth ultraviolet laser by Pr: YLF. Optics and Laser Technology, 2024, 569, 130812. DOI: https://doi.org/10.1016/j.optcom.2024.130812.

[16] Wang X, Liu J J, Li Q. Numerical analysis of thermal lensing effect in end-pumped Nd: YLF solid-state lasers. Acta Optica Sinica, 2022, 42(4): 0404001.

[17] Lang B T, Song Y J, Zong N, et al. Anisotropic thermal and polarized spectroscopic properties of Nd: YLF crystal. Journal of Luminescence, 2024, 276, 120838. DOI: https://doi.org/10.1016/j.jlumin.2024.120838.

[18] Kilinc M, Demirbas U, Gonzalez Diaz J B, et al. Thermal and population lensing of Yb:YLF at cryogenic temperatures. Optical Materials Express, 2023, 13(11): 3200-3212.  

[19] Jiang Z X, Li B X, Liao W B, et al. Performance study of blue weakly absorbed pumped Pr3⁺: YLF red laser. Chinese Journal of Lasers, 2024, 51(13): 1301003.

[20] Davide Baiocco, Ignacio Lopez-Quintas, Javier R Vázquez de Aldana, et al. Thermal analysis of diode-pumped femtosecond-laser gain media. Optics & Laser Technology, 2025, 180, 111499. DOI: https://doi.org/10.1016/j.optlastec.2024.111499.

[21] Eremeikin O N, Egorov N A, Zakharov N G, et al. Investigating a thermal lens in a Tm:YLF crystal under intense diode pumping. Journal of Optical Technology, 2009, 76(11): 676-679.