- Since 1962, for twenty years, I was with the semiconductor device group of the Werk fuer Fernsehelektronik (WF), Berlin, and engaged in the industrial development of semiconductor devices. I have been involved in the development of silicon crystal growth and high speed rectifiers, later of light emitting diodes (LED) basing on GaAsP and GaP, and the corresponding diagnostics. I became the head of the department for optoelectronic measurements, in 1967, and then for LED slice processing followed by the leadership for the transfer into the production. After that I changed to the research group for optoelectronic devices, in 1978, and was concerned there with flat panels and semiconductor lasers.

- In 1982 I joined the optoelectronics group of the Zentralinstitut fuer Elektronenphysik (ZIE) der Akademie der Wissenschaften der DDR, Berlin. As head of the department for research on heterojunctions I was responsible for investigations on ZnSe/ZnS flat panels, LEDs and laser diodes. Here especially AlGaAs and InGaAsP lasers have been investigated mainly with respect to their characterization and long-term behaviour, focusing on detection of the physical origins of laser diode degradation.

- In 1992, with foundation of the Ferdinand-Braun-Institut fuer Hoechstfrequenztechnik (FBH), Berlin, I could continue this work into the direction of semiconductor lasers with strained layer Quantum Wells. I became a project manager for semiconductor ridge waveguide (RW) lasers as pump sources for optical fibre communications, I was responsible for optoelectronic measurements on semiconductor lasers and finally I have participated in the development of high-power diode lasers.