Quantitative phase imaging based on Fresnel diffraction from a phase plate

Abstract

The structural complexity and instability of many interference phase microscopy methods are the major obstacles toward high-precision phase measurement. In this vein, improving more efficient configurations as well as proposing new methods are the subjects of growing interest. Here we introduce Fresnel diffraction from a phase step to the realm of quantitative phase imaging. By employing Fresnel diffraction of a divergent (or convergent) beam of light from a plane-parallel phase plate, we provide a viable, simple and compact platform for three-dimensional imaging of micron-sized specimens. The recorded diffraction pattern of the outgoing light from an imaging system in the vicinity of the plate edge can be served as a hologram, which would be analyzed via Fourier transform method to measure the sample phase information. The period of diffraction fringes is adjustable simply by rotating the plate without the reduction of both field of view and fringe contrast. The high stability of the presented method is affirmatively confirmed through comparison the result with that of conventional Mach-Zehnder based digital holographic method. Quantitative phase measurements on silica microspheres, onion skin and red blood cells ensure the validity of the method and its ability for monitoring nanometer-scale fluctuations of living cells, particularly in real-time.

Efficient methodology with potential uses of Fresnel diffractometry for real-time study of uniaxial nematic liquid crystal phase transitions

“…The first systematic and in-depth study of diffraction from a phase step was published by M. T. Tavassoly et al in the early 2000s 34 , and it has since expanded into a variety of technological fields over the past two decades 35 . Because of this, it has led to the development of numerous new optical metrology features and applications, such as the measurement of film thickness 36 , high-precision refractometry 37 , 38 , nanometer displacement measurement 39 , refractive index gradient in inhomogeneous phase objects and diffusion processes 35 , 40 , spectral modifications 41 – 43 , wavemetry 44 , real-time monitoring and measurement of chemical etching rate of transparent materials 45 , and 3D imaging 46 , 47 , alongside a lot of many other uses inspired by phase objects’ FD capabilities.…”

Fresnel Diffraction from Phase Steps and Its Applications

“…Finally, we should mention that the researchers have applied the Fresnel diffraction from a phase step to the measurements of the refractive index in X-ray region [23], film thickness [24][25][26], etching rate [27], simultaneous measurement of film thickness and refractive index [26], focal lengths of the lenses [28], specification of the spectral line profile [29], and modulation of phase function [30], Applications are increasing, particularly, in quantitative imaging of the phase objects in different scales [13,[31][32].…”

Quasi-common-path off-axis interferometric quantitative phase microscopy based on amplitude-division

“…Different from separated-path iQPMs, common-path iQPMs modulate the object beam and the reference beam into the same or almost the same path, so they are more stable, compact and robust against the noise. Various common-path iQPMs have been reported using two-aperture interferometric geometry [10][11][12][13][14][15][16]. For example, a double-aperture common-path interferometer [16] can introduce a carrier frequency by shifting the first lens or grating in a 4f optical imaging system without tilting the mirror or beam.…”