High power diode lasers in stack configuration find their largest applications in the medical instruments industry, in optical pumping of other laser types and in materials processing. In some areas diode lasers replace conventional Iasers. Other areas have emerged as new fields of applications for diode laser stacks over the last years.In order to employ diode laser systems successfully in the industrial market, advanced optical setups are used in connection with the diode laser stacks. Two groups of'these optical setups are discussed in this werk. First, a fiber coupled diode laser system is designed and realized including the nccessary technolcgical components such as beam rearrangement, polarization comblning, wavelength superposition and robust fiber coupling. The secend group of diode laser systems consists ofoptics that facilitate a continuously variable spot width.