Patent ID: 6025939
Filing Date: 2000-02-15
Classification: G02B,G03H,H01S

Abstract:
A tunable light source having an emission spectrum of substantially single lines, comprising:at least one active optical element;at least one first reflective surface;a grating with lines that are at least one of parallel and divergent, comprising a second reflective surface, said divergent lines diverging from at least one of a true vertex and an effective vertex, said grating and said at least one first reflective surface cooperating to form at least one resonant cavity that contains said at least one active optical element, said at least one active optical element and said at least one resonant cavity cooperating to produce at least one light output having an emission spectrum of substantially a single line, said at least one resonant cavity if comprising at least two resonant cavities said at least two resonant cavities having a relative orientation that is at least one of parallel and non-parallel;means for effecting a grazing coupling between said grating and said at least one resonant cavity and for controlling said grazing coupling to maintain substantially uniform distribution across substantially the entire grating of energy reflected from said at least one light output, said at least one resonant cavity being at least one of a resonant cavity without an optical fiber and a resonant cavity having an optical fiber, with said grating being controllably grazingly coupled to at least one of said resonant cavity having an optical fiber and said resonant, cavity without an optical fiber; andmeans for moving said grating along a path relative to said at least one resonant cavity to simultaneously and in the same ratio alter both the periodicity of the effective inter-sections of said grating with said at least one resonant cavity and the effective cavity length of said at least one resonant cavity to produce a constant longitudinal mode throughout the entire tuning range of said tunable light source.