Side-pumping Nd:YAG solar laser by six Fresnel lenses

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

To obtain a good compromise between collection efficiency and brightness figure of merit of solar-pumped lasers, a new side-pumping scheme is proposed. Firstly the solar radiations are collected and concentrated by six 700 mm diameter Fresnel lenses. The concentrated solar radiations are subsequently reflected by six plane folding mirrors with 95% reflectivity, into a common focal spot. This allows the concentration of 1740 W solar power with about 6.4 W/mm2peak solar flux. A secondary concentrator is composed of six aspheric fused silica lenses, positioned around a 40 mm radius fused silica sphere, compressing all the concentrated solar radiation from the six Fresnel lenses into an 8 mm diameter by 9 mm length Nd:YAG single-crystal rod. By positioning the spherical concentrator slightly above the aspherical lenses, a more uniform absorption profile is achieved. Mechanical support with a water cooling system ensures an efficient cooling to the laser medium. Optimal laser parameters are found through ZEMAX™ and LASCAD™ numerical analysis software. Only 16% of the solar power is absorbed by Nd:YAG medium. Solar laser power of 42.6 W is numerically calculated, reaching a collection efficiency of 18.5 W/m2. For a 400 mm plane-concave resonance cavity with –5m radius of curvature, M2x= M2y= 22 beam quality factors are numerically predicted. A near uniform pump absorption profile can be achieved by increasing the number of Fresnel lens and folding mirrors. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Original languageUnknown
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
Pagesnr. 878518
DOIs
Publication statusPublished - 1 Jan 2013
Event8th Iberoamerican Optics Meeting and 11th Latin American Meeting on Optics, Lasers, and Applications -
Duration: 1 Jan 2013 → …

Conference

Conference8th Iberoamerican Optics Meeting and 11th Latin American Meeting on Optics, Lasers, and Applications
Period1/01/13 → …

Cite this

Liang, D. (2013). Side-pumping Nd:YAG solar laser by six Fresnel lenses. In Proceedings of SPIE - The International Society for Optical Engineering (pp. nr. 878518) https://doi.org/10.1117/12.2026082