Variable-ratio radial-shearing interferometry with bifocal zone-plate twins

Compared to traditional radial-shearing interferometric systems, which can only adjust the radial-shearing ratio by replacing optical components or by using complex zoom lens systems, we propose a compact radial-shearing interferometer based on bifocal zone-plate twins, which can obtain two interference images with different radial-shearing ratios in a single measurement of the same state of the measured signal. At the same time, in combination with the UNet network, the central skeleton of the interference fringe is extracted for use in the iterative method of wavefront reconstruction. This method simplifies the optical hardware and image processing in wavefront sensing. This technology is expected to have strong application potential in the face of the real-time precision measurement challenges faced by the precision engineering of optical systems in astronomy and gravitational science.