Schmalbandige Laserquelle.

摘要

A narrowband laser source (Fig.3) includes an optical fiber section 17,26,27 including a core centered on a longitudinal axis and a cladding surrounding the core, and having a grating region (17)embedded in the core. The grating region includes a multitude of Bragg grating elements extending with a substantially equal longitudinal spacing substantially normal to the longitudinal axis for the grating region to significantly reduce the amount of light passing therethrough when the frequency of such light is in a predetermined narrow range around and including a predetermined center frequency, to an extent proportionate to the deviation of such frequency from the center frequency. A portion of the light emitted by a laser (23) at a frequency dependent on the amount of electric energy applied to the laser is supplied into the core of the fiber section (26) for propagation toward the grating region. The amount of light passing through the grating region (23) is detected (28), and the amount of energy applied to the laser is varied in dependence on the extent of deviation of the frequency of such light from the center frequency in such a sense as to reduce the extent of such deviation.