Patent ID: 8494317
Filing Date: 2013-07-23
Classification: G02B,H04J

Abstract:
1. A method for filtering an optical signal comprising a plurality of channels lying on a grid of optical frequencies equally spaced by a frequency spacing and occupying an optical bandwidth, the method comprising: operating an optical filter comprising resonators, each resonator having a respective free spectral range, wherein a first resonator is optically coupled to the optical signal and the remaining one or more resonators are optically coupled in series to the first resonator, so that a respective resonance of each one of the resonators falls within a first frequency band having bandwidth less than or equal to 15 GHz; first tuning at least one resonator with respect to at least another resonator to obtain a separation between a resonance of the at least one resonator and a resonance of the at least another resonator greater than or equal to 25 GHz; and second tuning the at least one resonator and the at least another resonator such that the respective resonance of each one of the resonators falls within a second frequency band, different from the first frequency band, having bandwidth less than or equal to 15 GHz; wherein during a period between and including the first tuning and the second tuning, at least one among the respective resonance of the at least one resonator and the respective resonance of the at least another resonator is tuned outside a frequency region spanning between, and including, the first and the second frequency band.