Wavelength tunable cw and pulsed semiconductor lasers with external fiber cavities for gas analysis

Two different semiconductor laser systems with external fiber cavities are presented. The first, self seeding, allows generation of short (20 ps) lase r pulses. Detailed investigations of the wavelength switching (which can re ach speeds up to the MHz range) are described. The second system is a mode hop free tunable cw system. Due to a new concept mode-hop free tuning can b e achieved by varying one (electrically controllable) parameter only. Gas s ensing applications are demonstrated for both systems.