Semiconductor lasers are used for example as sensors that scan the data stored on DVDs or Blu-Ray Discs. A special class of these semiconductor lasers, namely semiconductor disk lasers (SDLs), are due to their higher power and better focusing capability for example used for more advanced applications like skin cancer treatement. Unfortunately, these lasers are still limited in their output power to a certain extend, as the semiconductor rapidly heats up and looses its performance. To make these devices more powerful and extend their application fields, this research project aims on creating the laser emitting semiconductor part as a thin membrane and sandwiching it between diamond disks in a stacked arrangement. Diamond – the best thermal conductor available – keeps the semiconductor cool. By stacking we create artificial laser crystals, which can technically be treated in the same way as cassical solid laser crystals. Via the possibility of double-side pumping, which is not possible for SDLs, more semiconductor gain material can be included. Both, cooling and more gain material, will make these ALCs or membrane external-cavity surface-emitting lasers (MECSELs) more powerfull and enable more applications of this semiconductor membrane lasers in medicine and research.