Mode step-free, tuneable, spectrally clean laser light source has laser medium with resonator end mirror, imaging system, angle dispersing element, cat's-eye retroreflector and spatial filter

摘要

The laser light source has a laser medium including a resonator end mirror, an imaging system (22,24), an angle dispersing element (23) and a partially transparent reflector (26) placed at the focal point of the imaging system to form a substantially direction-independent cat's-eye retroreflector. A spatial filter (25) passes only spectrally filtered light to the reflector, resulting in the separation of fed back and output coupled useful light with high stability against components moving out of adjustment and reflector tilt.