Dual-wavelength resolution matching digital holographic microscopy using one path structured illumination

Abstract

A dual-wavelength resolution-matching digital holographic microscopy with one path structured illumination is presented, which can improve phase imaging resolution. In this configuration, a dual-wavelength hologram with two illumination modes corresponding to two different wavelengths can be flexibly recorded at one shot, and the imaging resolutions under the two wavelengths can reach equivalence by setting the modulation frequency of structure illumination. The expression for calculating the modulation frequency of structured illumination in a two-wavelength system is given. By setting the proper modulation frequency, the resolution of dual-wavelength phase imaging can be enhanced, which is verified in the phase imaging experiment of a USAF quantitative phase target. The dual-wavelength reconstructed phase map of paramecia cells exhibit the internal macronucleus, food vacuole and cilia. The imaging results demonstrate the resolution-matching approach using one path structured-illumination in effect for the improvement of phase imaging resolution.