Off-axis conjugate focusing optimization method based on aberration compensation

With the development of space solar power stations, the demand for high-efficiency and zero-obstruction solar concentrators is increasing. However, the existing technologies still face numerous challenges in terms of spot uniformity and aberration control. To address these issues, an off-axis conjugate point-focusing solar concentrator with a 500mm aperture and a focal ratio of 3 is proposed, along with its optical path optimization method. The concentrator consists of four parts:an off-axis primary mirror, a conjugate mirror, a planar reflector, and a sun-tracking mechanism. The off-axis primary mirror provides the main optical parameters; the conjugate mirror compensates for aberrations; and the planar reflector ensures precise positioning. Geometric construction methods are used to adjust the surface shape of the reflectors, constructing an accurate mathematical model, and analyzing the optical path using ray tracing methods. An optimization function targeting the main aberrations is constructed, and spot diagrams and irradiance maps are used to analyze the focal spot shape variations. By adjusting the reflective surface shapes of the off-axis primary mirror and the conjugate mirror, aberrations are effectively reduced, and the concentration ratio is improved. Detailed optical simulations are conducted under normal incidence and multi-angle incidence conditions to optimize the optical path design. Experiments conducted at an outdoor temperature of 10 degrees C demonstrate the aberration compensation effectiveness of the system. The optical concentration ratio exceeded 100, and the maximum focal temperature reached 372 degrees C. This study innovatively proposes an efficient off-axis conjugate focusing method, achieving zero obstruction, high concentration ratio, and high precision focusing through multi-level optimization techniques. The results indicate that this method has significant application potential in space solar power systems, providing a new solution for future solar energy utilization technologies.