The combination of solid-state lasers and semiconductor technology results in novel lasers with excellent properties. The book describes modern high-power laser diodes, criteria for the selection of suitable laser materials, designs of typical laser systems (pumping arrangement, crystal geometry, resonators), and provides a detailed description of diode-pumped lasers such as high-power lasers, single frequency lasers, lasers of new wavelengths, and miniature lasers. Finally, applications and development opportunities are discussed.