High-efficiency solar-pumped TEM00-mode Nd:YAG laser

• 4.5 W CW TEM00-mode (M2 ≤ 1.1) 1064 nm solar laser is both simple and compact.
• 2.36% TEM00-mode slope efficiency is 3.37 higher than the previous record.
• Record-high TEM00-mode solar laser collection efficiency of 4.0 W/m2 is achieved.

Here we report a significant progress in solar-pumped laser slope efficiency and collection efficiency by pumping a 4.0 mm diameter grooved Nd:YAG single-crystal rod with a heliostat–parabolic mirror solar energy concentration system. The incoming solar radiation is firstly collected and focused by the system. An ellipsoid-shaped fused silica concentrator is then used to further compress the concentrated solar radiation into the grooved rod within a 2V-shaped pumping cavity. 4.5 W continuous-wave TEM00-mode (M2≤1.1) 1064 nm solar laser power is finally measured, attaining 2.36% laser slope efficiency, which is 3.37 and 2.91 times higher than previous records by Fresnel lens and parabolic mirror respectively. Record-high TEM00-mode solar laser collection efficiency of 4.0 W/m2 is also achieved.