Optical field modulation for phase imaging: A unified framework for interferometric and diffractive strategies

Abstract

Compared with conventional intensity imaging, complex optical field imaging enables the recovery of both amplitude and phase information of the optical field, and has become an important tool in label-free microscopy, surface metrology, and crystal characterization. However, because conventional detectors can only measure intensity and cannot directly record phase, complex field reconstruction is an ill-posed inverse problem that heavily relies on physical constraints and computational priors. Optical field modulation offers an effective solution by imposing known, controllable modulations into the illumination, propagation, reference, or detection path, improving the observability and recoverability of phase information. Optical field modulation increases the measurement diversity and improves the solvability of the inverse problem, reducing reconstruction ambiguity and improving robustness to noise and missing data. This review establishes a unified framework that classifies optical-field modulation according to the measurement mechanism and modulation location, and compares different strategies in terms of information diversity, identifiability, acquisition efficiency, calibration burden, and dynamic adaptability.