Development of solar concentrators for high-power solar-pumped lasers.

Area of Science:

• Optics and Photonics
• Renewable Energy Engineering

Background:

• Solid-state lasers are crucial for various applications, but their efficiency and power output are often limited by pumping methods.
• Solar-pumped lasers offer a sustainable alternative to traditional lamp-pumping, but achieving high efficiency and power remains a challenge.

Purpose of the Study:

• To develop and characterize unique solar concentrators for solar-pumped solid-state lasers.
• To improve the efficiency and laser output power of solar-pumped solid-state lasers.
• To explore the potential applications of the developed light-guide lens technology.

Main Methods:

• Utilized a 2m x 2m Fresnel lens as a primary solar concentrator.
• Employed a cone-shaped hybrid concentrator to confine solar power.
• Coupled solar power to a laser rod using a liquid light-guide lens (LLGL) with surrounding coolant.
• Performed analytical and experimental characterization of the cylindrical LLGL performance.

Main Results:

• Achieved 120 W continuous wave (cw) laser output with a 14 mm diameter LLGL and a 6 mm x 100 mm Nd:YAG laser rod.
• Obtained a beam quality factor M2 of 137 and an overall slope efficiency of 4.3%.
• Demonstrated a collection efficiency of 30.0 W/m², 1.5 times higher than the previous record.
• Reached an overall conversion efficiency exceeding 3.2%, comparable to commercial lamp-pumped lasers.

Conclusions:

• The developed solar concentrator and LLGL system significantly enhances solar-pumped solid-state laser performance.
• The high collection efficiency and overall conversion efficiency represent a substantial improvement over previous records.
• The light-guide lens concept shows promise for applications beyond solar lasers, including concentrator photovoltaics and other solar energy optics.