Quantitative phase imaging by common-path interferometric microscopy: application to super-resolved imaging and nanophotonics

Abstract

Quantitative phase imaging needs of a holographic setup in order to retrieve the sample phase distribution. Often this new phase information is obtained at the cost of reducing the useful range in other parameters of the imaging system such as field of view or resolution. We devised an experimental setup that allows complex amplitude evaluation and phase image quantification of three-dimensional (3-D) samples in widefield digital holographic microscopy. The basis is a common-path interferometric configuration that can be implemented in two configurations depending on the position and the basic period of the grating: static grating and windowed Fourier filtering method or with phase-shifting moving grating. Both configurations allow complex amplitude recovery and, thus, quantitative phase imaging of the sample under test. Moreover, by combining the basic setup with tilted illumination and time multiplexing, it is possible to generate a synthetic aperture enlargement that improves the final image resolution. Experimental results validated our concepts.

Spatially multiplexed interferometric microscopy with partially coherent illumination

“…SMIM is based on a CPI architecture using input plane spatial multiplexing and a 1-D diffraction grating to allow holographic recording. SMIM was previously validated as demonstrator at the lab [44][45][46] and implemented in a regular microscope. 43 In the latter validation, SMIM allows holographic imaging in a regular microscope by three small modifications: a coherent illumination source, a 1-D diffraction grating, and a specific input plane spatial distribution.…”

“…43 The method, named spatially multiplexed interferometric microscopy (SMIM), rises from our previously developed spatially multiplexed common-path interferometric layout tested on an optical table and under super-resolution purposes. [44][45][46] SMIM simply replaces the broadband light source of the conventional microscopy by a laser diode, it leaves a clear region at the input plane for reference beam transmission, and it properly places a one-dimensional (1-D) diffraction grating in the microscope embodiment. With these three minimal modifications, a regular microscope is converted into a holographic one working under off-axis holographic recording.…”

Single-Element Reflective Digital Holographic Microscopy

“…That situation is common in microscopy and can be used in our system to optimize the recording process, that is, to only record the useful interferogram. It would nevertheless be worthwhile to mention that different technical aspects such as the spatial frequency of the grating, the magnification of the system, the pixel size of the digital sensor, and the axial distances between the grating, the microscope lens and the digital sensor must be properly adjusted when implementing the technique [29,39,40].…”

Single-shot, dual-mode, water-immersion microscopy platform for biological applications

“…Because of its interferometric underlying principle, DHM has been implemented using different classical interferometric configurations [29][30][31][32][33][34] being the most used one the Mach-Zehnder interferometric layout [8,9,11,12,17,19]. Nevertheless and considering illumination by transmission, common-path interferometric (CPI) configuration [35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51] provides significant advantages over all previous architectures. In CPI, both the imaging and the reference beams follow nearly the same optical path because both are transmitted in parallel through the same microscope lens.…”

“…Once transmitted, both beams are properly overlapped at the recording plane [48][49][50][51]. This type of parallel transmission can be accomplished by the specific constraints of the input plane design: a black region at the input plane in side-by-side configuration with the sample [48][49][50] or by back-reflection at the tilted coverslip of a specially designed chamber [51] for transmissive and reflective configurations, respectively. And after that, both beams are overlapped allowing holographic recording by using minimal elements (diffraction gratings and tube lenses).…”