Spatio-angular filter (SAF) imaging device for deep interrogation of scattering media.

Optical microscopy is limited to shallow interrogation depths as high-resolution imaging in scattering media is challenging. Current methods require complex and expensive experimental setup or suffer from low resolution. Through gating of photons exiting the scattering media using a restricted numerical aperture (NA) fiber optic plate (FOP), we establish a novel spatio-angular filter imaging device that allows deeper imaging in scattering media.

Holographic formation and diffractive properties of hybrid periodic structures.

The paper presents formation processes and diffraction properties of hybrid periodic structures such as volume gratings with refractive index modulation, on the surface of which relief gratings are formed. It is shown experimentally that relief gratings with significant diffraction properties in used photopolymer materials are formed in a narrow range of exposure parameters. It is established that the formation of a relief grating on the surface of a volume grating leads to significant changes in the selective properties of structures.

Glycerol dehydration of native and diabetic animal tissues studied by THz-TDS and NMR methods.

The optical clearing method has been widely used for different spectral ranges where it provides tissue transparency. In this work, we observed the enhanced penetration of the terahertz waves inside biological samples (skin, kidney, and cornea) treated with glycerol solutions inducing changes of optical and dielectric properties. It was supported by the observed trend of free-to-bound water ratio measured by the nuclear magnetic resonance (NMR) method.

Non-labeled lensless micro-endoscopic approach for cellular imaging through highly scattering media.

We describe an imaging approach based on an optical setup made up of a miniature, lensless, minimally invasive endoscope scanning a sample and matching post processing techniques that enable enhanced imaging capabilities. The two main scopes of this article are that this approach enables imaging beyond highly scattering medium and increases the resolution and signal to noise levels reaching single cell imaging. Our approach has more advantages over ordinary endoscope setups and other imaging techniques.

Reversible and irreversible alterations of the optical thickness of PQ/PMMA volume recording media samples. Part I: Experiment.

Experimental research into changes of the optical thickness of phenanthrenequinone-doped polymethyl methacrylate samples in the process of irradiation by a 473 nm laser is presented. It was demonstrated that heating-induced reversible changes lead to a decrease in the optical thickness. The temperature coefficient of the relative changes of the optical thickness was measured to be -1.