Microthermography of diode lasers: The impact of light propagation on image formation

We analyze the effect of propagating infrared thermal radiation within a diode laser on its thermal image taken by a thermocamera. A ray-tracing analysis shows that this effect substantially influences image formation on a spatial scale of 10 mu m, i.e., in the domain of microthermography. The main parameter affecting the thermal radiation spread in the semitransparent semiconductor structure is the free carrier concentration in the substrate, governing its absorption. Two applications are presented: a quantum dot laser and a quantum-well laser, where independent thermal models are developed using the finite element method (FEM). Our ray-tracing analysis verifies the FEM simulated temperature profiles by interlinking them to experimental temperature maps obtained through microthermography. This represents a versatile experimental method for extracting reliable bulk-temperature data from diode lasers on a microscopic scale

Spatial-Mode Discrimination in Guided and Antiguided Arrays of Long-Wavelength VCSELs

Three means of optical confinement imposed on InAlGaAs/InP 1.3 mu m VCSEL arrays are investigated with self-consistent numerical model of laser operation. Laterally patterned tunnel junction (TJ), in-build guiding realized with air-gap patterning, and antiguiding schemes are investigated and optimized to achieve single-mode operation. The analysis shows that mode discrimination in laterally patterned TJ is very responsive to the injected current, the air-gap patterning reduces influence of the working conditions and supports multimode operation, and finally, antiguiding schemes provide single-mode operation for prescribed geometrical design

Mobbing as polymorphic social problem

In study the mobbing was introduced as new the phenomenon pathological, which it stood with serious social problem, it steps out under different figures and it is connected with plaguing psychical mainly, the discrimination as well as the persecution in place of work. The analysis of notion ,,mobbing” was executed, its specific, cause was showed as well as solutions protecting workers' environment before this phenomenon. Publication in synthetic from shows how to perceive, and to diagnose mobbing in order to can it counteract effectively before he it will take real dimension