Pitch-Switchable Metalens Array for Wavefront Profiling at Multiwavelength

Abstract

The wavefront sensor is a crucial component in the adaptive optics system (AOS), responsible for detecting aberrated wavefronts. However, The Shack–Hartmann wavefront sensor with single-pitch microlens array is limited in its adaptability to different observing conditions, affecting wavefront reconstruction accuracy. And conventional microlens arrays are wavelength-specific. Here, a polarization-dependent pitch-switchable metalens array based on non-interleaved silicon metasurfaces is proposed, capable of working at multiple wavelengths. By controlling the incident and outgoing light polarization, three metalens arrays with customized pitches can be switched at will. Furthermore, achromatic performance is achieved in the 950 nm and 1030 nm wavelengths through structural dispersion engineering. Finally, wavefront detection experiments are finally conducted to demonstrate the phase reconstruction with variable spatial resolution. The metalens array with high flexibility in wavefront sensor can further enhance the adaptability of AOS and has great potential for applications in light-field imaging, and machine vision, etc.