The focusing properties of the optimized zone plate structures which have upper and lower zones with different thicknesses are studied by the three-dimensional finite-difference time-domain method. Two kinds of materials are chosen, including silver representing metal and BK7 glass representing dielectric. An optimization algorithm is applied to tune the parameters of zone plate structures. Sev...

We report on the accurate measurement of nonlinear ellipse rotation (NER) by means of a phase-sensitive method employing a dual-phase lock-in. The magnitudes and signs of pure refractive electronic nonlinearities of silica and BK7 were determined with this new method using 150 femtosecond (fs) laser pulses at 775 nm. Experimental and theoretical analyses of the NER signal were carried out and t...

Ray tracing Particle Image Velocimetry (RT-PIV) is an optical technique for high resolution velocity measurements in challenging systems, such as transparent packed beds, that uses ray to correct distortions introduced by geometries the light paths. The based correction a post processing step applied raw PIV particle images before classical evaluation. In this study, RT-PIV performed top layer ...

Abstract The relaxation of free electron–hole pairs generated after proton irradiation is modelled by means a simplified set hydrodynamic equations. model describes the coupled evolution pair and self-trapped exciton (STE) densities, along with electronic lattice temperatures. equilibration excitations based on two-temperature model, while two mechanisms for are considered: STE formation Auger ...

Sensing abilities of a one-dimensional photonic crystal (1DPhC) represented by multilayer dielectric structure are analyzed theoretically and experimentally, using new wavelength interrogation interference method. The comprising glass substrate six bilayers TiO 2 /SiO with termination layer is employed in both gas sensing based on the Bloch surface wave (BSW) resonance liquid analyte self-refer...

We propose a novel, high-contrast imager called a polarization interferometric nulling coronagraph (PINC) for direct detection of extrasolar planets. The PINC uses achromatic half-wave plates (HWPs) installed in a fully symmetric beam combiner based on polarizing beam splitters. Jones calculus suggests that a stellar halo suppression level of 10(-10) can be achieved at 5 lambda/D for a broad wa...

The detection of molecules at an ultralow level by Surface-Enhanced Raman Spectroscopy (SERS) has recently attracted enormous interest for various applications especially in biological, medical, and environmental fields. Despite the significant progress, SERS systems are still facing challenges for practical applications related to their sensitivity, reliability, and selectivity. To overcome th...