Fraunhofer Society

About: Fraunhofer Society is a government organization based out in Munich, Germany. It is known for research contribution in the topics: Laser & Silicon. The organization has 24736 authors who have published 40168 publications receiving 820894 citations.

High-power fibre lasers

Abstract: High-power fibre lasers are in demand for industrial, defence and scientific applications. This review provides an overview of the present state of the art in the field and discusses present challenges and the future outlook.

Improved quantitative description of Auger recombination in crystalline silicon

Abstract: An accurate quantitative description of the Auger recombination rate in silicon as a function of the dopant density and the carrier injection level is important to understand the physics of this fundamental mechanism and to predict the physical limits to the performance of silicon based devices. Technological progress has permitted a near suppression of competing recombination mechanisms, both in the bulk of the silicon crystal and at the surfaces. This, coupled with advanced characterization techniques, has led to an improved determination of the Auger recombination rate, which is lower than previously thought. In this contribution we present a systematic study of the injection-dependent carrier recombination for a broad range of dopant concentrations of high-purity $n$-type and $p$-type silicon wafers passivated with state-of-the-art dielectric layers of aluminum oxide or silicon nitride. Based on these measurements, we develop a general parametrization for intrinsic recombination in crystalline silicon at 300 K consistent with the theory of Coulomb-enhanced Auger and radiative recombination. Based on this improved description we are able to analyze physical aspects of the Auger recombination mechanism such as the Coulomb enhancement.

A unified framework for coupling measurement in object-oriented systems

Abstract: The increasing importance being placed on software measurement has led to an increased amount of research developing new software measures. Given the importance of object-oriented development techniques, one specific area where this has occurred is coupling measurement in object-oriented systems. However, despite a very interesting and rich body of work, there is little understanding of the motivation and empirical hypotheses behind many of these new measures. It is often difficult to determine how such measures relate to one another and for which application they can be used. As a consequence, it is very difficult for practitioners and researchers to obtain a clear picture of the state of the art in order to select or define measures for object-oriented systems. This situation is addressed and clarified through several different activities. First, a standardized terminology and formalism for expressing measures is provided which ensures that all measures using it are expressed in a fully consistent and operational manner. Second, to provide a structured synthesis, a review of the existing frameworks and measures for coupling measurement in object-oriented systems takes place. Third, a unified framework, based on the issues discovered in the review, is provided and all existing measures are then classified according to this framework. This paper contributes to an increased understanding of the state-of-the-art.