We previously established that spectroscopic microscopy can quantify subdiffraction-scale refractive index (RI) fluctuations in a label-free dielectric medium with a smooth surface. However, to study more realistic samples, such as biological cells, the effect of rough surface should be considered. In this Letter, we first report an analytical theory to synthesize microscopic images of a rough ...

We present an analytical method that yields the real and imaginary parts of the refractive index (RI) from low-coherence interferometry measurements, leading to the separation of the scattering and absorption coefficients of turbid samples. The imaginary RI is measured using time-frequency analysis, with the real part obtained by analyzing the nonlinear phase induced by a sample. A derivation r...

In a recent article, Pierscionek et al. [1] reported non-invasive measurements of the age dependence of refractive index distribution in human eye lenses in vitro using a novel X-ray Talbot Interferometry method. In their paper, the authors make frequent reference to our own work in which we employed magnetic resonance imaging (MRI) to make similar non-invasive measurements of the refractive in...

ZnO and ZnO: Mn nanocrystals synthesized via reverse micelle method. The structural properties nanocrystals were investigated by XRD and Transmission electron microscopy (TEM). The XRD results indicate that the synthesized nanocrystals had a pure wurtzite (hexagonal phase) structure. The various optical properties of these nanocrystals such as optical band gap energy, refractive index, dielectr...

We adapted the critical angle method for measuring rough surfaces under partial contact to acquire an in vivo skin refractive index (RI). Assuming that the total reflection is the simple sum of reflection from areas that are in contact and reflection from those that are not in contact, the RI can be estimated even for partial contact with a rough surface. We found that cheek skin is sufficientl...

In this work, we are interested in the denaturation process of a laccase from Tramates versicolor via the determination of the refractive index, the refractive index increment and the specific volume in various media. The measurements were carried out using an Abbe refractometer. We have shown that the refractive index increment values obtained from the slope of the variation of the refractive ...

We report a new technique for non-invasively mapping the refractive index distribution through the eye lens using magnetic resonance micro-imaging. The technique is applied to map the refractive index distribution throughout the sagittal plane of 18 human eye lenses ranging in age from 14 to 82 years in vitro. The results are compared with standard models for the human eye lens. They confirm th...

An advanced dielectric function has been designed to compute the photonic band structures of non-close-packed inverse opals fabricated using conformal infiltration and by a recently described sacrificial-layer technique. A model is proposed to correctly simulate complex dielectric structures resulting from conformal backfilled infiltrations. While large photonic band gaps PBGs and a reduced ref...

It has been proposed that the visual system is able to estimate the refractive index of thick transparent objects from background distortions caused by them. More specifically, it was hypothesized that this is done based on a mid-level cue, the distortion field, whose computation from the input requires comparing the part of the background seen through the object with the part visible in plain ...