Design and simulation study of a monolithic metalens-based compact interferometer for quantitative phase imaging

Abstract

Digital holography (DH) is a widely used quantitative phase imaging technique for label-free 3D characterization. Conventional digital holographic systems are bulky and alignment-sensitive with multiple optical components, limiting their compactness and stability. In this simulation study, a monolithic, polarization-insensitive, metalens-based holographic interferometer is presented, replacing conventional setups with a compact, robust, and alignment-free configuration. Finite-difference time-domain simulations were performed to evaluate hologram formation, reconstruction, and magnification, along with signal-to-noise ratio (SNR) and phase sensitivity. Further changes in modulation transfer function, Strehl ratio, focusing efficiency, focal length, wavefront error, SNR, and phase sensitivity were simulated to verify the design’s robustness to temperature variations, fabrication errors, and wavelength variations. The demonstrated off-axis holographic configuration may be used in applications such as digital holographic microscopy, contactless optical profilometry, Fourier holography, and point-of-care devices.