Energy, Vol.44, No.1, 593-603, 2012
High-efficiency concentrated optical module
A high-efficiency optical module that comprises a parabolic reflector, a parabolic second optical element (SOE), and a Fresnel/aspheric concentrating lens is proposed. It is fabricated by high-precision machine tools based on an optimum design obtained using ray-tracing software simulations. The actual profiles of the reflector and SOE before coating the thin film are compared to the designed profiles to investigate the dimension errors and their influence on optical performance. The total flux, the optical efficiency, and the minimum, maximum, and mean irradiances are evaluated for various ray sources using ray-tracing simulations of the ASTM G173-03 spectrum. The optical module achieves good optical performance and its light irradiance distribution on the chip surface is uniform. The peak value of the irradiance spectrum is over three times that obtained without using the collection module. The concentrating lens thus improves the optical efficiency of the module and irradiance uniformity. The optical efficiency of the optical module with a concentrating lens is as high as 91% and the total flux exceeds 3 W. This efficiency is higher than those reported in the literature. (C) 2012 Elsevier Ltd. All rights reserved.