2. Direct-emitting solid-state laser systems in the UV-visible range

2.1 Large-gap semiconductor lasers (green-gap issues)

Many systems and applications today rely on the use of semiconductor lasers emitting in the near- and mid-infrared range. The most powerful of these are ternary or quaternary compounds such as AlGaAs or InGaAs, which emit laser radiation at fixed frequencies around 800 and 980 nm. As we shall see, these semiconductor lasers can be used either as optical pumping sources for other laser systems (§ 2.3 ), or directly but with the addition of a frequency...