The overall sensitivity of frontside-illuminated, silicon single-photon avalanche diode (SPAD) arrays has often suffered from fill factor limitations. loss can however be recovered by employing microlenses, whereby the challenges specific to SPAD are represented large pixel pitch (> 10 µm), low native (as as ∼10%), and size (up mm). In this work we report on implementation refractive microlenses means photoresist masters, used fabricate molds for imprints UV curable hybrid polymers deposited...

In patients with predisposing risk factors, bacterial colonization of dental implants can lead to periimplantitis (PI). Established individual treatment protocols be effective, but antimicrobial resistance (AMR) and biofilm formation may impede successful treatment, therefore requiring surgical intervention. Photodynamic Inactivation (PDI) combined optical waveguides could eradicate such pathogens without the new AMR emergence reduce need for surgery. this pilot study, we investigated...

In many clinical applications it is relevant to observe dynamic changes in oxygenation. Therefore the ability of imaging with time domain (TD) near-infrared optical tomography (NIROT) will be important. But fast a challenge. The data acquisition our handheld TD NIROT system based on single photon avalanche diode (SPAD) camera and 11 light sources was consequently accelerated. We tested diffusive medium simulating tissue moving object embedded. With 3D image reconstruction, correctly located...

Fluorescence molecular tomography (FMT) emerges as a powerful non-invasive imaging tool with the ability to resolve fluorescence signals from sources located deep in living tissues. Yet, accuracy of FMT reconstruction depends on deviation assumed optical properties actual values. In this work, we improved initial required for using new-generation time-domain (TD) near-infrared (NIROT) system, which effectively decouples scattering and absorption coefficients. We proposed multimodal paradigm...

Near infrared optical tomography (NIROT) is an emerging modality that enables imaging the oxygenation of tissue, which a biomarker tremendous clinical relevance. Measuring in reflectance usually required when NIROT applied scenarios. Single photon avalanche diode (SPAD) array technology provides compact solution for time domain (TD) to gain huge temporal and spatial information. This makes it possible image complex structures tissue. The main aim this paper validate wavelength normalization...

In a turbid medium such as biological tissue, near-infrared optical tomography (NIROT) can image the oxygenation, highly relevant clinical parameter. To be an efficient diagnostic tool, NIROT has to have high spatial resolution and depth sensitivity, fast acquisition time, easy use. Since many tissues cannot penetrated by light, tissue needs measured in reflection mode, i.e., where light emission detection components are placed on same side. Thanks recent advance single-photon avalanche...

The processes of formation and digital recording interference patterns arising in partially coherent polychromatic light the course monitoring surface microrelief objects having stratified volume structure are considered. expressions for intensity distribution pattern depending on relief object derived taking spectral properties photodetector array into account. results numerical simulation fringes experimentally measured white microinterferograms presented. These demonstrate agreement...

To increase the spatial resolution of near-infrared optical tomography, we successfully designed and tested a 32×32 time-resolved SPAD image sensor with unprecedented sensitivity in fast acquisition speed.

Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency of preterm infant. Low abdominal tissue oxygen saturation (StO2) measured by near-infrared spectroscopy (NIRS) oximetry may be an early sign NEC relevant for treating or even preventing NEC. However, current commercial NIRS oximeters provide inaccurate StO2 readings because they neglect stool as absorber. To tackle this problem, we determined optical properties faeces infants to enable a correct measurement. In 25...

Time-domain near-infrared optical tomography (TD NIROT) techniques based on diffuse light were gaining performance over the last years. They are capable of imaging tissue at several centimeters depth and reveal clinically relevant information, such as oxygen saturation. In this work, we present very first in vivo results our SPAD camera-based TD NIROT reflectance system with a temporal resolution ∼116 ps. It provides 2800 time flight source-detector pairs compact probe only 6 cm diameter....

We present the first laboratory results of new generation time domain near-infrared optical tomography setup, which is based on a time-of-flight 32×32 SPAD camera with high photon detection probability in NIR range.

Experimental setup of diffraction phase microscope (DPM) with double low-coherence lighting system is presented in the paper. Algorithm interference picture processing and optical thickness, height, volume mean cells (MCV) RBC calculating shown. We demonstrate results experiments blood smears ability method to calculate 3D model biological shape. Investigation change dynamics morphology after injection glucose for diabetes by DPM shown

The method of autocorrelation low coherence interferometry is proposed for diagnostics inhomogeneities and the internal structure layered technical biological samples. In this optical field reflected from sample analysed by using a Michelson interferometer. Because object outside interferometer, distance between interferometer under study not limited thus can move during measurements. Theoretical substantiation media with discrete continuous modifications presented.

Nowadays is developed a lot of techniques for the refractive index measurements. One them describe in this article. We are used method optical microscopy, there diffraction phase microscopy with transmissionreflection illumination measurements red blood cells (RBCs) index. Theory and results experiments also presented

Fourier optics approach is employed in the work do describe formal theory of diffraction phase microscope (DPM). Final expression for optical field registration plain given. Optimal spatial filter diameter and numerical aperture calculated theoretically. DPM used reconstruction map red blood cells slide. The windows influence on shown experimentally.

The possibility of improving white-light full-field optical coherence tomography (OCT) resolution by image sensor colour balance tuning is shown numerically. We calculated the full-width at half-maximum (FWHM) a pulse registered silicon under various settings. calculations were made for both halogen lamp and white LED sources. results show that interference width can be reduced proper choice coefficients. reduction up to 18%, as compared with regular settings, 20%, monochrome sensor.