Solar laser pumping approach for both simultaneous and stable multibeam operation under tracking error condition

A solar laser pumping approach to achieve both simultaneous and stable multibeam solar laser operation under solar tracking error condition is proposed here. By using a heliostat, solar radiation is firstly redirected to a parabolic mirror, secondarily concentrated by an aspheric lens, and finally absorbed by four Nd:YAG rods within a pump cavity using a homogenizer. Zemax (R) and LASCAD (TM) analysis demonstrate that four simultaneous and stable 1064-nm continuous-wave solar laser emissions with similar multimode power levels can be achieved even with azimuthal solar tracking errors up to +/- 0.5 deg. The variation on the multimode solar laser power of the four rods is significantly reduced from 32.38% and 55.52% without the homogenizer to 0.00% and 0.21% with the homogenizer for +/- 0.1 deg and +/- 0.2 deg azimuthal solar tracking error, respectively. More importantly, simultaneous and stable TEM00 mode solar laser emissions from the four rods are also numerically attained under solar tracking error condition. (c) 2023 Society of Photo-Optical Instrumentation Engineers (SPIE) [DOI: 10.1117/1.JPE.13.028001]

Automated summary

This study proposes a solar laser pumping approach that achieves simultaneous and stable multibeam solar laser operation even under solar tracking error condition. By redirecting solar radiation using a heliostat to a parabolic mirror, then concentrating it with an aspheric lens, and finally absorbing it with four Nd:YAG rods within a pump cavity using a homogenizer, four simultaneous and stable 1064-nm continuous-wave solar laser emissions with similar multimode power levels can be achieved. The use of the homogenizer significantly reduces the variation in multimode solar laser power of the four rods for different azimuthal solar tracking errors.