Patent ID: 6865315

Claim:
A dispersion compensating filter comprising: a. a first optical cavity for receiving an optical signal beam from a direction corresponding to a first side, the optical cavity comprising; i. a first thin film spacer, and ii. a first pair of dielectric reflector stacks surrounding the first thin film spacer, b. a second optical cavity having a first side disposed toward and in optical communication with the second side of said first optical cavity to provide a transmission bandwidth BW, the second optical cavity comprising; i. a second thin film spacer, and ii. a second pair of dielectric reflector stacks surrounding the second thin film spacer, c. a reflector disposed in optical communication with the second side of said second optical cavity, the reflector characterized by a reflectivity of greater than about 95% over a bandwidth BWR, d. wherein the optical coupling of the first and second optical cavity provides a maxima in group delay GD(λ) over bandwidth BW at a center wavelength position wherein BW is less than BWR, and e. the physical thickness of the first and second thin film spacers are less than about 200 microns.