Phase-shifting point-diffraction interferometry with common-path and in-line configuration for microscopy

Abstract

A new common-path and in-line point-diffraction interferometer for quantitative phase microscopy is proposed. The interferometer is constructed by introducing a grating pair into the point-diffraction interferometer, thus forming a common-path and in-line configuration for object and reference waves. Achromatic phase shifting is implemented by linearly moving one of the two gratings in its grating vector direction. The feasibility of the proposed configuration is demonstrated by theoretical analysis and experiments.

Common path interferometer based on the modified Michelson configuration using a reflective grating

“…It should also be noted that the lateral resolution of the setup is limited by the pixel size of the CCD camera due to the unitary magnification of the system. In fact, the diffraction-limited resolution can be achieved using a microscopic objective with high magnification, as many others did [13][14][15]26,27].…”

Violation of the Lagrange invariant in an optical imaging system

“…These characteristics seem simple, but as far as we know they have not previously simultaneously existed in any classical, physical lens based imaging system or classical holography imaging system, such as [11]. While in the FINCH system, these characteristics exist simultaneously.…”

Near-Common-Path Self-Reference Quantitative Phase Microscopy

“…The single-shot fringe patterns are typically analyzed using Fourier or Hilbert transform methods in order to extract the sample phase information [5], [6]. Related QPM work includes the demonstration of an in-line point-diffraction-interferometry configuration with optimized lateral resolution [7]. More recent work by the same group demonstrates quantitative phase imaging using Zernike phase contrast microscopy [8] (as distinct from holographic interferometry), providing both high lateral resolution and low coherent noise.…”