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Selected semiconductor nanostructures provide extremely localized coherent light sources. Here an ensemble of CdS nanostructures was excited by UV/vis femtosecond laser pulses and their ultrafast luminescence characteristics were investigated as functions of the pulse energy fluence and the photon quantum energy. All optical Kerr gating enabled studies of the emission dynamics with a time resolution of 150 fs avoiding any influence on the CdS emission. The initially observed emission built up after a delay of 0.1−3 ps and decayed rapidly in a biexponential way, strongly dependent on both the laser energy fluence and the quantum energy. The central wavelength of the emission spectrum revealed a significant blue-shift within the first few ps followed by a transient red-shift relative to spontaneous excitonic emission of CdS. All findings are mainly attributed to stimulated radiative carrier recombination in the laser excited electron−hole plasma after its thermalization with the CdS lattice.

The study of asymmetrically self-reversed lines emitted by inhomogeneous gas discharges has been made on the basis of an extension of the multiparameter method. A new procedure has been developed which makes it possible to determine the line broadening at the arc axis, its radial variation, and the ratio shift/width. An investigation is made into the effect of these quantities on the determination of the plasma temperature. The proposed method has been applied to high-pressure mercury discharges operating on dc and ac (50 Hz) using the mercury line 5461 Å. The pressure broadening in the impact approximation has been measured to be (1.43±0.11)×104 mÅ atm−1  K0.7; the corresponding line shift is towards the blue line wing.

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The impact of the different reconstruction parameters in super-resolution structured illumination microscopy (SIM) onto artifacts is carefully analyzed. They comprise the Wiener filter parameter, an apodization function, zero-frequency suppression and modifications of the optical transfer function. A detailed investigation of the reconstructed image spectrum is concluded to be suitable for identifying artifacts. For this purpose, two samples, an artificial test slide and a more realistic biological system, were used to characterize the artifact classes and their correlation with the image spectra as well as the reconstruction parameters. In addition, a guideline for efficient parameter optimization is suggested and the implementation of the parameters in selected up-to-date processing packages (proprietary and open-source) is depicted.