ABSTRACT Quantitative phase imaging (QPI) based on holographic interferometry is widely used in biophotonics and precision metrology. While on‐axis systems are compact and stable, the need for multiple recordings limits imaging speed. Off‐axis designs enable single‐shot imaging but increase complexity and sensitivity. We present a compact module that combines the advantages of both approaches by converting any on‐axis interferometer into a single‐shot system. Single‐shot QPI is achieved through coherence gating and precise optical path matching within the module. The concept is demonstrated with a Mirau objective but is readily applicable to other established types of on‐axis interferometers. Coherence gating removes long‐standing limitations of Mirau setups, enabling imaging of wet‐mount samples and real‐time phase measurements. This advances Mirau interferometry toward dynamic studies in biology, fluidics, and micromechanics. Demonstrations include QPI of human cells, time‐resolved imaging of streaming red blood cells, visualization of evaporation dynamics in liquid mixtures, and motion monitoring of an atomic force microscope cantilever at 100 Hz.
Bouchal et al. (Fri,) studied this question.