Quantitative phase imaging via Fresnel biprism-based digital holographic microscopy

Abstract

We present a simple and stable quantitative phase imaging technique via Fresnel biprism-based digital holographic microscopy. A Fresnel biprism is used to divide the incoming beam and generate self-referencing common-path configuration. So, high contrast hologram is produced in overlapping area. To evaluate the performance of Fresnel biprism with different refringence angles, the system magnification and length are discussed in detail. In addition, different sources of illumination, such as laser and LED, are used in proposed system for studying the feasibility of quantitative phase imaging. The temporal stability of system is also illustrated by comparing with the Mach-Zehnder-based off-axis digital holographic setup. It is shown that the proposed scheme has sub-nanometer temporal stability (~0.109𝑛𝑚) due to the common-path geometry. The experiments on micro-lens array, biological cell and water droplet are reported demonstrating its application both for static and dynamic samples. The refractive index measurement results of polyester fiber also further demonstrate the effectiveness of the proposed system.