An optimization method to measure chromatic aberration with Shack-Hartmann wavefront sensor

The Shack-Hartmann wavefront sensor (SHWFS) is widely used in adaptive optics, laser beam shaping, optical testing, and other fields. Traditional Shack-Hartmann wavefront sensors are primarily used to measure monochromatic wavefront aberrations. In the measurement of human eye aberrations, the Shack-Hartmann wavefront sensor has been employed to measure longitudinal chromatic aberrations and transverse chromatic aberrations of the human eye, but most methods are based on filter-based measurements, i.e., separately measuring the monochromatic wavefront aberrations of different wavelengths. This paper proposes a chromatic aberrations measurement method based on the spot array image of the multi-wavelength Shack-Hartmann wavefront sensor. The method uses the spot images, and based on phase retrieval principles, applies an improved particle swarm optimization algorithm and BFGS algorithm jointly to reduce the error function, thereby determining the wavefront aberrations of multiple wavelengths of light, and the difference of which is the chromatic aberrations. This way, the method achieves comprehensive measurement of wavefront aberrations and chromatic aberrations.