The new approach to the theoretical description of the thermal Casimir force between real metals is presented. It uses the plasma-like dielectric permittivity that takes into account the interband transitions of core electrons. This permittivity precisely satisfies the Kramers-Kronig relations. The respective Casimir entropy is positive and vanishes at zero temperature in accordance with the Ne...

We measure the mechanical thermal noise of soft silicon atomic force microscope cantilevers. Using an interferometric setup, we obtain a resolution down to 10(-14) m Hz(-1/2) on a wide spectral range (3-10(5) Hz). The low frequency behavior depends dramatically on the presence of a reflective coating: almost flat spectra for uncoated cantilevers versus a 1/f like trend for coated ones. The addi...

We report time-domain measurements with subpicosecond resolution of optical tunneling of terahertz electromagnetic pulses undergoing frustrated total internal reflection. Measurements of the transmitted electromagnetic pulses over a 3 THz bandwidth permits direct determination of frequency-dependent phase and amplitude changes in both the thin and opaque barrier limits in a single measurement. ...

We use our recently developed beam-deflection technique to measure the dispersion of the nondegenerate nonlinear refraction (NLR) of direct-gap semiconductors. The magnitude and sign of the NLR coefficient n2(ωa; ωb) are determined over a broad spectral range for different values of nondegeneracy. In the extremely nondegenerate case, n2(ωa; ωb) is positively enhanced near ...

A pitch-synchronous method and system for speech coding using timbre vectors is disclosed. On the encoder side, speech signal is segmented into pitch-synchronous frames without overlap, then converted into a pitch-synchronous amplitude spectrum using FFT. Using Laguerre functions, the amplitude spectrum is transformed into a timbre vector. Using vector quantization, each timbre vector is conver...

Optical properties of plasmas, including dielectric constants, indices of refraction, and absorption coefficients, are determined from an average-atom point of view. Linear response of an average atom to an harmonic electric field leads to an averageatom version of the Kubo-Greenwood formula, which is used to calculate the frequencydependent electric conductivity of the plasma. The frequency-de...