Patent ID: 6507438
Filing Date: 2003-01-14
Classification: G02B

Abstract:
A system for dynamically tuning a multi-path interference filter comprising:an input optical pathway that transmits an input beam having a range of different wavelengths; an output optical pathway that transmits an output beam confined within an optical waveguide in a fixed position with respect to an optical axis; an optical path length difference generator interconnecting the input and output optical pathways having a plurality of intermediate pathways that (a) extend in a direction of beam propagation, (b) exhibit different effective refractive indices, and (c) transmit separate portions of the input beam through different optical path lengths; the different optical path lengths of the intermediate pathways being arranged to subject a first portion of the range of different wavelengths to constructive interference and a second portion of the range of different wavelengths to destructive interference; a first of the intermediate pathways having a refractive index that varies relative to a second of the optical pathways with a change in ambient conditions; and a tuner that produces temporary changes in the ambient conditions affecting the refractive index of the first intermediate pathway to vary a spectral power distribution of the output beam in the same fixed position with respect to the optical axis.