The interaction of 10.6 μm laser radiation with liquids

The interaction of a pulse from a TEA laser with the free liquid surface of water and chloroform, is recorded by high-speed photography. The phenomena is similar to the high velocity impact of a projectile with a liquid or solid surface.\ud \ud A vapour cloud, above the liquid, expands with an initial velocity of 1500 m s−1 and a violent disturbance below the liquid surface is observed. In the case of chloroform, a cloud of small bubbles is produced. A shock wave model is proposed to account for the disturbance below the surface of the liquid

The influence of cell window imperfections on the calibration and measured data of two types of rotating-analyzer ellipsometers

A graphical method has been developed to determine the plane of incidence in the presence of cell windows with small retardation. For two types of rotating-analyzer ellipsometers, expressions have been derived that relate the experimental parameters and the elements of the Mueller imperfection matrices of the windows. These matrices can be determined by measuring with and without cell windows. Measurements have been performed with three samples with different optical constants

Novel fast spectroscopic rotating-polarizer ellipsometer

A fast spectroscopic rotating-polarizer ellipsometer has been developed. The machine is equipped with a cascade arc as a light source, a 1024 element linear photodiode array for parallel data processing, and a fast data acquisition interface that allows for hardware averaging of the data prior to transmission to the controlling computer. The ellipsometer has been mounted on an ultrahigh vacuum chamber. As an example the sublimation of an As cap layer from ErAs/GaAs(100) was studied in situ. Fourier spectra in the range from 1.5 to 4.0 eV with an accuracy and precision better than 2×10-2 and 3×10-4, respectively, are obtained within 1.7 s. The spectral response of the photodiode array is presently the factor limiting the energy range