The successful use of high power diode lasers (HDL), which are based on 1 cm semiconductor bars, is critically linked to the optimization of output power, beam quality, reliability, and cost. Even though some criteria can be improved only on the costs of others, the common point of concern is the reliability. A defined reliability allows the user to estimate not only the investment costs but also all service and replacement costs. All those economical concerns can be translated into technical requirements. All efforts to fulfill these technical requirements are part of JENOPTIK Laserdiode"s LongLifeTechnology.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.