LOW COST MEANS OF MODULATING A LASER

摘要

The present invention discusses a modulation method and apparatus for modulating an extended-cavity laser (211). The method and apparatus (200-203) entails the use of each pulse in an input modulating pulse train as the trigger for the generation of a brief or "notch" pulse, i.e. a pulse that briefly diminishes the normal drive current. Each "notch" pulse is used to drive the semiconductor laser (211) embedded in an extended cavity with a current that flows opposite to its normal drive current. This serves to diminish the inverted charge-carrier population essential to lasing action, so the laser output falls sharply in a form of amplitude modulation. The invention also discloses a simple, miniaturized means (372, 352, 312) of micropositioning, based on the differential rotation of nested conical plugs, that can serve to couple the semiconductor laser to the cavity.