Using a broadband through-transmission technique, the attenuation coefficient and phase velocity spectra have been measured for a set of multi-wall carbon nanotube (MWCNT)-nylon composites (from pure nylon to 20% MWCNT by weight) in the ultrasonic frequency band from 4 to 14 MHz. The samples were found to be effectively homogeneous on spatial scales from the low end of ultrasonic wavelengths in...

We calculate by molecular dynamics the optical functions of MgO in the far infrared region 100-1000 cm(-1), for pressures up to 40 GPa and temperatures up to 4000 K. An ab initio parametrized many-body force field is used to generate the trajectories. Infrared spectra are obtained from the time correlation of the polarization, and from Kramers-Kronig relations. The calculated spectra agree well...

This course describes the interaction of electromagnetic radiation in the “optical” part of the spectrum (microwaves, infrared visible, ultraviolet) with matter—metals, insulators, semiconductors, and superconductors. Topics covered include the following. 1. Maxwell’s equations and plane waves in matter. 2. The refractive index N and the complex dielectric function, . 3. Semiclassical theories ...

Holographic microscopy is an emerging biological technique that provides amplitude and quantitative phase imaging, though the contrast provided by many cell types and organelles is low, and until now no dyes were known that increased contrast. Here we show that the metallocorrole Ga(tpfc)(SO3)2, which has a strong Soret band absorption, increases contrast in both amplitude and phase and facilit...

We explore the mathematical theory to rigorously describe response of media with linear time-varying, generally dispersive, electromagnetic constitutive parameters. show that even when temporal inhomogeneity takes place on a time scale comparable or shorter than driving fields' period, one can still define physically meaningful time-varying dispersion. Accordingly, generalized set Kramers-Kroni...

transmittance and reflectance, the imaginary part can be determined from transmittance data alone. It is possible to use Kramers-Kronig analysis to calculate the real part if the imaginary part is known over a sufficiently broad range. We show that the delta calculated from reflection and transmission data without taking into account roughness may underestimate the real part of the refractive i...

Optical spectra were investigated in a spectral range of (300 - 700) nm for CuAlS2 single crystals. Transmission and wavelength modulated transmission demonstrated presence some impurity absorption bands the region optical transparency functions (real imaginary components dielectric function, refractive index extinction coefficient) have been calculated from reflection by means Kramers-Kronig r...