RESUMO
The pursuit of high-power solar laser systems with high efficiency and capacity for large tracking error compensation is determinant for the applicability of this renewable technology. A side-pumped dual-rod Ce:Nd:YAG solar laser was developed and tested at the focus of a 2 m diameter parabolic concentrator. Maximum continuous-wave total solar laser power of 58 W was measured. To the best of our knowledge, this is the highest laser power from a Ce:NdYAG solar laser. Moreover, wide tracking error compensation width of 5.1° in the azimuthal direction was reached, being 4.25 times higher than the previous measurement without solar tracking assistance.
RESUMO
Solar laser technology typically requires a highly accurate solar tracking system that operates continuously, which increases energy consumption and reduces the system's lifetime. We propose a multi-rod solar laser pumping approach to enhance solar laser stability under non-continuous solar tracking conditions. Using a heliostat, solar radiation is redirected toward a first-stage parabolic concentrator. At its focus, an aspheric lens further concentrates the solar rays onto five Nd:YAG rods positioned within an elliptical-shaped pump cavity. Numerical analysis using Zemax and LASCAD software showed that the tracking error width at 10% laser power loss for the five 6.5 mm diameter and 15 mm length rods was 2.20°, which is 50% higher than that of the solar laser in previous non-continuous solar tracking experiments. 2.0% solar-to-laser conversion efficiency was also attained.
RESUMO
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.
RESUMO
A scalable TEM(00) solar laser pumping approach is composed of four pairs of first-stage Fresnel lens-folding mirror collectors, four fused-silica secondary concentrators with light guides of rectangular cross-section for radiation homogenization, four hollow two-dimensional compound parabolic concentrators for further concentration of uniform radiations from the light guides to a 3 mm diameter, 76 mm length Nd:YAG rod within four V-shaped pumping cavities. An asymmetric resonator ensures an efficient large-mode matching between pump light and oscillating laser light. Laser power of 59.1 W TEM(00) is calculated by ZEMAX and LASCAD numerical analysis, revealing 20 times improvement in brightness figure of merit.
RESUMO
A hydrogenated amorphous silicon (a-Si:H) photosensor was explored for the quantitative detection of a HIV-1 virion infectivity factor (Vif) at a detection limit in the single nanomolar range. The a-Si:H photosensor was coupled with a microfluidic channel that was functionalized with a recombinant single chain variable fragment antibody. The biosensor selectively recognizes HIV-1 Vif from human cell extracts.
