Micromachines (Oct 2022)

Highly Efficient Four-Rod Pumping Approach for the Most Stable Solar Laser Emission

  • Miguel Catela,
  • Dawei Liang,
  • Cláudia R. Vistas,
  • Dário Garcia,
  • Hugo Costa,
  • Bruno D. Tibúrcio,
  • Joana Almeida

DOI
https://doi.org/10.3390/mi13101670
Journal volume & issue
Vol. 13, no. 10
p. 1670

Abstract

Read online

We report a significant numerical improvement in multi-rod laser efficiency, with an enhanced solar tracking error compensation capacity for a heliostat-parabolic system. The solar laser head was composed of a fused silica conical lens and a single conical pump cavity ensuring multiple passes through four 4.55 mm diameter, 15 mm length Nd:YAG rods. 0.76° tracking error width at 10% laser power loss, and total multimode laser power variation of 0.05% at ±0.1° solar tracking error and 0.30% at ±0.2° solar tracking error were numerically calculated, being 1.27, 74.80 and 21.63 times, respectively, more than the experimental record in solar tracking error compensation capacity attained with a dual-rod side-pumping horizontal prototype pumped by the same heliostat-parabolic system. Additionally, the end-side-pumping configuration of the four-rod solar laser-enabled 43.7 W total multimode solar laser power, leading to 24.7 W/m2 collection efficiency and 2.6% solar-to-laser power conversion efficiency, being 1.75 and 1.44 times, respectively, more than that experimentally obtained from the dual-rod side-pumping prototype. The significant improvement in solar tracking error compensation capacity with a highly efficient end-side-pumping configuration is meaningful because it reduces the cost of high-precision trackers for solar laser applications.

Keywords