Experimental study on high-precision phase diversity wavefront sensing using a distorted grating

Phase diversity using a distorted grating is recognized as an effective wavefront sensing technique. The distorted grating is capable of simultaneously generating multiple images with specific diversity phases, offering advantages such as high efficiency of phase diversity image acquisition and resistance to vibrations. However, the application and development of this technique have been limited due to the lack of experimental validation for achieving high-precision wavefront sensing. In this study, a distorted grating was designed and fabricated to produce three defocused images. An improved Broyden-Fletcher-Goldfarb-Shanno (BFGS) algorithm was employed to enhance the stability and efficiency of the phase diversity algorithm when processing large-scale data from multiple images. Experimental verification was conducted using an off-axis two-mirror optical system, and the results demonstrated that this method achieves high-precision wavefront sensing. This paper aims to contribute to the promotion and broader application of phase diversity with distorted grating.