High beam quality of nanosecond Nd:YAG slab laser system with SBS-PCM

Ding, Jianyong; Yu, Guangli; Fang, Chunqi; Wang, Jianlei; Zheng, Ruilin; Li, Binbin; Zhou, Jun; Zhu, Xiaolei; Wei, Wei

doi:10.1016/j.optcom.2020.126273

Cited by 8 publications

(1 citation statement)

References 17 publications

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“…In existing laser systems with low repetition rates, the SBS-PCM has reached the joule level in terms of energy load and achieved reflectivity exceeding 90%. Wavefront aberrations have been effectively corrected through the phase conjugation properties, resulting in excellent beam quality near the diffraction limit in SBS-PCM systems [23][24][25][26][27][28] . However, few studies have studied the output characteristics of SBS-PCMs under repetitive pumping conditions [29,30] .…”

Section: Introductionmentioning

confidence: 99%

Characteristics and suppression of beam distortion in a high repetition rate nanosecond stimulated Brillouin scattering phase conjugation mirror

Chen,

Tan,

Jin

et al. 2024

High Pow Laser Sci Eng

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The stimulated Brillouin scattering phase conjugation mirror (SBS-PCM) based on liquid media is widely used in highpower laser systems due to its robust thermal load capacity, high energy conversion efficiency and improved beam quality. Nevertheless, with an increase in the pump repetition rate, thermally-induced blooming and optical breakdown can emerge, leading to distortions in the Stokes beam. In this study, we delved into the thermal effects in liquid SBS-PCMs employing hydrodynamic analysis, establishing a relationship between beam profile distortion and the thermal convection field. We calculated the temperature and convection velocity distribution based on the pump light parameters and recorded the corresponding beam profiles. The intensities of the beam profiles were modulated in alignment with the convection directions, reaching a velocity peak of 2.85 mm/s at a pump pulse repetition rate of 250 Hz. The residual sum of squares (RSS) was employed to quantify the extent of beam profile distortion relative to a Gaussian distribution. The RSS escalated to 7.8, in contrast to 0.7 of the pump light at a pump pulse repetition rate of 500 Hz. By suppressing thermal convection using a high-viscosity medium, we effectively mitigated beam distortion. The RSS was reduced to 0.7 at a pump pulse repetition rate of 500 Hz, coinciding with a twentyfold increase in viscosity, thereby enhancing the beam quality. By integrating hydrodynamic analysis, we elucidated and mitigated distortion with targeted solutions. Our research offers an interdisciplinary perspective on studying thermal effects and contributes to the application of SBS-PCMs in high-repetition-rate laser systems by unveiling the mechanism of photothermal effects.

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