Method and apparatus for servo-based spectral array alignment in optical systems

An optical apparatus comprising:

• a) an input port, providing a multi-wavelength optical signal and a reference signal;
• b) a wavelength-disperser, for separating said multi-wavelength optical signal and said reference signal by wavelength into multiple spectral channels and a reference spectral component in a spectral array with a predetermined relative arrangement;
• c) a beam-receiving array including a reference-wavelength-sensing element and a plurality of beam-receiving elements, positioned such to receive corresponding ones of said reference spectral component and said spectral channels;
• and
• d) a servo-control unit for maintaining said reference spectral component at a predetermined location on said reference-wavelength-sensing element, so as to maintain a particular alignment between said spectral channels and said beam-receiving elements.

An optical apparatus comprising:

• a) an input port, providing a multi-wavelength optical signal and first and second reference signals;
• b) a wavelength-disperser that separates said multi-wavelength optical signal and said first and second reference signals by wavelength into multiple spectral channels and first and second reference spectral components having a predetermined relative arrangement;
• c) a beam-focuser that focuses said spectral channels along with said first and second reference spectral components into corresponding focused spots in a spectral array with said predetermined relative arrangement;
• d) a beam-receiving array, including first and second reference-wavelength-sensing elements and a plurality of beam-receiving elements, positioned such to receive said first and second reference spectral components and said spectral channels respectively;
• and
• e) a first alignment-adjusting element that adjusts an alignment between said spectral array and said beam-receiving array, so as to enable said first reference spectral component to be aligned at a first predetermined location on said first reference-wavelength-sensing element and said second reference spectral component to be aligned at a second predetermined location on said second reference-wavelength-sensing element.