Optical and electrophysical properties of Cz-grown zinc doped p -GaAs samples have been investigated. Middle-infrared reflection spectra ten obtained. Galvanomagnetic Van der Pau measurements made on these also, the values resistivity Hall coefficient calculated. All experiments carried out at room temperature.Reflection processed by Kramers–Kronig relations. The spectral dependences real imagi...

Abstract Along the lines of the nonlinear response theory developed by Ruelle, in a previous paper we have proved under rather general conditions that Kramers-Kronig dispersion relations and sum rules apply for a class of susceptibilities describing at any order of perturbation the response of Axiom A non equilibrium steady state systems to weak monochromatic forcings. We present here the first...

We calculate the nondegenerate bound electronic nonlinear refractive index n2 ( w1; w2) (i.e., an index change at frequency w1 due to the presence of a beam at frequency w2) in semiconductors. We calculate this nonlinearity and its disper~ sion using a Kramers-Kronig transformation on the calculated nondegenerate nonlinear absorption spectrum due to two-photon absorption, electronic Raman and o...

The broadband, coherent nature of narrow-linewidth fiber frequency combs is exploited to measure the full complex spectrum of a molecular gas through multiheterodyne spectroscopy. We measure the absorption and phase shift experienced by each of 155 000 individual frequency-comb lines, spaced by 100 MHz and spanning from 1495 to 1620 nm, after passing through hydrogen cyanide gas. The measured p...

The limitations on scattering amplitudes imposed by causality requirements are deduced from the demand that the commutator of field operators vanish if the operators are taken at points with space-like separations. The problems of the scattering of spin-zero particles by a force center and the scattering of photons by a quantized matter field are discussed. The causality requirements lead in a ...