Inelastic light scattering in crystals has historically been treated as a spatially incoherent process, giving rise to incoherent optical radiation. Here we demonstrate that Raman scattering can be spatially coherent, in which case it depends on the dimensionality and symmetry of the scatterer. Using near-field spectroscopy, we measure a correlation length of ∼30  nm for the optical phonons in ...

We suggest a new approach for selective trapping of light absorbing particles in gases by multiple optical bottle-beam-like traps created by volume speckle field. We demonstrate stable simultaneous confinement of a few thousand micro-particles in air with a single lowpower laser beam. The size distribution of trapped particles exhibits a narrow peak near the average size of an optical speckle. ...

We present a new theoretical and numerical framework for the study of the optical properties of micrometric and nanometric three-dimensional structures of arbitrary shape. We show that the field distribution induced inside and outside such a structure by different external monochromatic sources can be obtained from a unique generalized field propagator expressed in direct space. An application ...

Abstract This study has reported about the preparation and characterization of Copper oxide (CuO) nanoparticles doped with Cobalt series at low temperature by Sol‐gel method. The techniques like X‐ray diffraction (XRD), scanning electron microscope (SEM), Raman spectroscopy, defused reflectance spectroscopy (DRS), DC measurement have been used to confirm its phase formation, that is, monoclinic...

We numerically investigate the propagation of light through the photonic crystal (PhC) waveguide on low refraction index material for near-field light focusing at the visible wavelength (635 nm) by incorporating a center air slot and Fabry-Perot resonator on the scanning tip. Perturbations by water and substrate refraction index changes of the PhC are analyzed by the finite-difference time-doma...

Using the atomistic pseudopotential method complemented by configuration interaction calculations, we have studied the electronic and optical properties of ZnO nanowires (NWs) in the presence of quantum confinement effects. Our results indicate that the near-band-edge exciton experiences a crossover from an in-plane polarized A-exciton (for D≥ 3 nm) to an out-of-plane polarized C-exciton (for D...

Over, the past decade researchers have come up with a new technology, named "Plasmonics" which has the potential of realizing miniaturized nanophotonic circuits, having the compactness of electronic circuit and the bandwidth of photonic networks. In plasmonic waveguides, the optical guidance is mediated by the electromagnetic wave propagating along a metal/dielectric interface, which arises due...

Introduction: Quantum cascade (QC) lasers are very important optical sources that can cover the whole mid-infrared range (3–15 mm) for gas sensing, industrial process monitoring, and military applications [1]. They have become even more interesting for commercial applications in recent years because of their successful growth by metal organic vapour phase epitaxy (MOVPE) [2–6] technology, which...

Nanoposts of 10–40 nm top diameter on an InGaN/GaN quantum well structure were fabricated using electron-beam lithography and inductively coupled plasma reactive ion etching. Significant blue shifts up to 130 meV in the photoluminescence (PL) spectrum were observed. The blue-shift range increases with decreasing post diameter. For nanoposts with significant strain relaxation, the PL spectral pe...

Photonic crystal fibre (PCF)–fibre bragg grating (FBG) integration opens up new possibilities in multi-parameter fibre-optic sensing, owing to their active control over light characteristics and mode confinements. Their integration results in a mismatch in their mode field diameters (MFDs), which in turn causes various types of losses such as confinement loss, scattering loss, etc. This paper p...