Related papers: Index of refraction engineering in five level DIGS…
The aim of this research is to reconstruct the 3D X-ray refractive index gradient maps by the proposed vector Radon transform and its inverse, assuming that the small-angle deviation condition is met. Theoretical analyses show that the…
Reflective Intelligent Surfaces (RIS) are considered promising in improving coverage in Non-Line of Sight (NLOS) wireless links, especially at mm wave or higher frequency bands. Coverage provided by RIS is here compared to coverage from…
A proximity focusing ring imaging Cherenkov detector, with the radiator consisting of two or more aerogel layers of different refractive indices, has been tested in 1-4 GeV/c pion beams at KEK. Essentially, a multiple refractive index…
At resonance, the optical response of a homogeneous medium to incident light is governed by temporal dispersion, which induces changes in the refractive index (RI). However, recent experimental results reveal RI enhancements exceeding the…
Electromagnetically-induced transparency has become an important tool to control the optical properties of dense media. However, in a broad class of systems, the interplay between inhomogeneous broadening and the existence of several…
A nanometer-thin-cell (in the direction of laser beam propagation) has been elaborated with the thickness of the atomic vapor column varying smoothly in the range of $L = \unit[50-1500]{nm}$. The cell allows one to study the behavior of the…
This paper proposes a non-computational method of counteracting the effect of image degradation introduced by the diffraction phenomenon in lensless microscopy. All the optical images (whether focused by lenses or not) are diffraction…
We experimentally show the spectrally averaged nonlinear refractive index and absorption coefficient for liquid water, water vapor, {\alpha}-pinene, and Si using a full-phase analysis in the terahertz regime through a standard time-domain…
It is demonstrated that an object distribution can be successfully retrieved from its diffraction pattern or hologram, even if some of the measured intensity samples are missing. The maximum allowable number of missing values depends on the…
We have implemented a multi-functional optofluidic sensor that can monitor changes in the refractive index and pressure of biofluid simultaneously and can detect free-solution molecular interaction in-situ. In this paper, we demonstrate two…
We uncover and identify the regime for a magnetically and ferroelectrically controllable negative refraction of light traversing multiferroic, oxide-based metastructure consisting of alternating nanoscopic ferroelectric (SrTiO$_2$) and…
Immersed reflection gratings improve spectral resolving power by enabling diffraction within a high refractive index medium. This principle has been widely adopted to make grating spectrometers more compact. Conventional immersed gratings…
Nonlinear selective reflection from the interface YAG window-high density rubidium vapor in the high-temperature cell is studied at the transition 5S$_{1/2}$-5P$_{3/2}$. In the experiment tunable pump and probe lasers are used. The…
Using a density matrix approach, we study the simplest systems that display both gain and feedback: clusters of 2 to 5 atoms, one of which is pumped. The other atoms supply feedback through multiple scattering of light. We show that, if the…
We developed a phase correction method for broadband terahertz time-domain spectroscopy in reflection geometry, which allows us to obtain quantitative and accurate values for the complex refractive index of materials. The process is…
Gradient index (GRIN) fibers are used to improve the design of many fiber optic devices. However, the properties of the GRIN fiber must be determined to optimally engineer a device which incorporates GRIN fiber components. The index of…
Refractive Index Tomography is the inverse problem of reconstructing the continuously-varying 3D refractive index in a scene using 2D projected image measurements. Although a purely refractive field is not directly visible, it bends light…
In previous works we presented a novel multiparametric sensor to simultaneously measure the refractive index and the speed of sound in a liquid by means of the acousto-optic effect. The sensor requires an illumination system that expands…
Image reconstruction under multiple light scattering is crucial in a number of applications such as diffraction tomography. The reconstruction problem is often formulated as a nonconvex optimization, where a nonlinear measurement model is…
Atom interferometry is the most successful technique for precision metrology. However, current interferometers using ultracold atoms allows one to probe the interference pattern only momentarily and has finite duty cycle, resulting in an…