H. Rossmann

Molecular beam epitaxial growth and characterization of ZnSe on GaAs

Abstract Systematic investigations have been performed concerning the effect of growth temperature and beam pressure ratio on the structural perfection and optical properties of molecular beam epitaxy (MBE) grown ZnSe on GaAs substrates. A surface phase diagram of ZnSe has been derived showing the different surface reconstructions as a function of these growth conditions. RHEED reflex profiling reveals more details about the surface morphology occurring in different stages of the growth process. The epitaxial layers are further characterized by means of X-ray diffraction and various optical techniques.

Nonlinear optical properties of wide-gap II–VI bulk semiconductors and microcrystallites

Abstract We summarize experimental data on nonlinear refraction and absorption in bulk II–VI compounds and present low-power applications in optical bistability and self-diffraction. We report on measurements of the switching transients on the fs time-scale. Based on data for specially prepared II–VI-doped glasses we discuss the nonlinear optical response in the situation of strong zero-dimensional quantum confinement. We report on the observation of the DC Stark effect on CdS quantum dots.

Optical Nonlinearity and Bistability of Wide-Gap II-VI Compounds

We report on optical nonlinearity and bistability at room temperature in the wavelength range from 500 to 700 nm. The underlying physical mechanisms are discussed and low-power operation as well as fast switching on the ps time-scale is demonstrated.

Optical nonlinearity and bistability of CdS

Abstract Experimental data concerning the nonlinear optical behaviour of CdS are reported. At cryo-temperatures an increasing nonlinear absorption at the exciton resonance is observed, with the aid of which optical hysteresis is demonstrated. At room-temperature saturation of the band-edge absorption is found at intensities as low as 10 kW/cm2. The switch-on time is determined to be smaller than 6 ps.

Growth and characterization of CdTe/ZnTe buffer layers on GaAs substrates

Abstract The MBE growth of ZnTe, CdTe, (Cd,Zn)Te and related superlattice structures on (001)GaAs has been investigated. Growth rate, structural perfection and mixed crystal composition have been determined as functions of different growth parameters. Optical properties and the ability of blocking substrate impurities with a superlattice structure have been studied.