OPTICAL ALL-PASS FILTERS FOR PHASE RESPONSE DESIGN WITH APPLICATIONS FOR DISPERSION COMPENSATION

Lossless all-pass optical filters are introduced, which can approximat e any desired phase response while maintaining a constant, unity ampli tude response. Architectures using cascade and lattice structures base d on ring resonators and cavities defined by reflectors are discussed. Two applications are presented: 1) for fiber dispersion compensation and 2) for compensation of the nonlinear phase response of narrow band pass optical filters such as thin-film or Bragg grating filters. All o rders of dispersion can be compensated in principle, and the filters a re periodic so multiple channels can be compensated with a single devi ce. The architectures are very compact compared to alternatives such a s chirped Bragg gratings.