Durable low refractive index thin films with anti-reflection properties were successfully fabricated using chitin nanofibers (CHINF) obtained from crab shell. The low refractive index film was achieved by forming porous thin films; the porosity was produced by increasing the number of airspaces inside the membrane. The layer-by-layer (LBL) method was used to achieve the effective stacking of th...

In-line holographic microscopy of micrometer-scale colloidal spheres yields heterodyne scattering patterns that may be interpreted with Lorenz-Mie theory to obtain precise time-resolved information on the refractive index of the suspending medium. We demonstrate this approach to spatially resolved refractometry with measurements on calibrated refractive index standards, and use it to monitor ch...

This paper presents an effective integration scheme of nanostructured SnO2 with the fiber optic platform for chemical sensing applications based on evanescent optical interactions. By using a triblock copolymer as a structure directing agent as the means of nano-structuring, the refractive index of SnO2 is reduced from >2.0 to 1.46, in accordance with effective medium theory for optimal on-fibe...

In this paper, the effect of pressure, temperature and impurity on the energylevels, binding energy, linear and nonlinear optical properties of a modified Gaussianquantum dot are studied. In this regard, the finite element method is employed to solvethe single electron Schrodinger equation in the effective mass approximation with andwithout impurity at the center of the dot. In addition, the en...

The combined effects of hydrostatic pressure and temperature on the optical absorption coefficient and refractive index changes of a hydrogenic impurity in a disc-shaped quantum dot with parabolic confinement in the presence of an external electric field have been investigated by using the perturbation method within the effective-mass approximation. Analytical expressions for the linear and thi...

To identify the composition of interstellar dust grains by their absorption spectra requires accurate knowledge of their optical properties. The presence of inclusions or voids within grains can alter their refractive indices. Here, we examine the suitability of applying the Maxwell-Garnett mixing theory to highly porous grains. It is found that the effective refractive index obtained for heter...

The refractive index as well as molar refraction, is the true index of purity of substance and plays a vital role in solution chemistry. A small addition of a foreign substance either in solid state of liquid form is going to effect the refractive index.As such the variation of refractive indices in pure glucose solution as a function of concentration is studied in detail and this principle is ...

Tunable acoustic gradient index TAG lenses create tunable multiscale Bessel beams. These lenses are fluid-filled cylindrical cavities within which an acoustic radial standing wave is excited. This standing wave modulates the density, and thereby the refractive index within the lens. Spatial gradients in the refractive index can be used for lensing. A predictive model for the steady-state fluid ...

Zero index materials where sound propagates without phase variation, holds a great potential for wavefront and dispersion engineering. Recently explored electromagnetic double zero index metamaterials consist of periodic scatterers whose refractive index is significantly larger than that of the surrounding medium. This requirement is fundamentally challenging for airborne acoustics because the ...