Geometric-Phase Microscopy for Quantitative Phase Imaging of Isotropic, Birefringent and Space-Variant Polarization Samples

Abstract

We present geometric-phase microscopy allowing a multipurpose quantitative phase imaging in which the ground-truth phase is restored by quantifying the phase retardance. The method uses broadband spatially incoherent light that is polarization sensitively controlled through the geometric (Pancharatnam-Berry) phase. The assessed retardance possibly originates either in dynamic or geometric phase and measurements are customized for quantitative mapping of isotropic and birefringent samples or multi-functional geometric-phase elements. The phase restoration is based on the self-interference of polarization distinguished waves carrying sample information and providing pure reference phase, while passing through an inherently stable common-path setup. The experimental configuration allows an instantaneous (single-shot) phase restoration with guaranteed subnanometer precision and excellent ground-truth accuracy (well below 5 nm). The optical performance is demonstrated in advanced yet routinely feasible noninvasive biophotonic imaging executed in the automated manner and predestined for supervised machine learning. The experiments demonstrate measurement of cell dry mass density, cell classification based on the morphological parameters and visualization of dynamic dry mass changes. The multipurpose use of the method was demonstrated by restoring variations in the dynamic phase originating from the electrically induced birefringence of liquid crystals and by mapping the geometric phase of a space-variant polarization directed lens.

Polarization-Sensitive Digital Holographic Imaging for Characterization of Microscopic Samples: Recent Advances and Perspectives

“…As example, the images obtained for human cheek cells are reported in Figure 9d. Results are very impressive, since they demonstrated an accuracy well below 5 nm, opening new research directions in the quantitative retardance imaging of anisotropic biological samples [76].…”

“…Finally, the instantaneous (single-shot) measure of the spatial variations of the phase retardance induced in either geometric or dynamic phase is carried out through an alternative approach presented in Ref [76], where a quantitative fourth-generation optics microscopy (Q4GOM) has been developed; even though this approach doesn't characterize the full SoP, thanks to its unique optical performance, it can open new research in diagnosis of optical composite nanostructures or biomolecular sensing. The phase restoration is based on the self-interference of optical wave and is achieved in an intrinsically stable common-path setup.…”

Twisted Rainbow Light and Nature‐Inspired Generation of Vector Vortex Beams

“…This module was designed as a common‐path interferometric system, which uses polarization control of light to record off‐axis incoherent holograms. [ 56,57 ] The module combines Leith's and Upatnieks' implementation of an achromatic off‐axis interferometer [ 58 ] with operation of a geometric phase grating (GPG) (Supporting Information, Part SI 4). The GPG is placed at the image plane of the lens CL 1 and acts as a polarization‐sensitive diffractive beamsplitter directing $${|R\rangle}$$ and $${|L\rangle}$$ components of the rainbow light into −1st and +1st diffraction orders.…”

One-shot phase-recovery using a cellphone RGB camera on a Jamin-Lebedeff microscope

“…Microscopy is a powerful tool not only for investigation of the micro-structure of an object but also for quantification of local properties of the sample. One such property is the optical path difference (OPD) of the light passing through biological matter, which is known to be closely related to the dry mass per area density of biological matter [1, 2].…”