Patent ID: 7532789

Claim:
An apparatus comprising an optical bus arm; a ring resonator arm; first, second and third directional couplers between the optical bus arm and the ring resonator arm; a first tuner on one of the optical bus arm and the ring resonator arm between the first directional coupler and the second directional coupler; a second tuner on other of the optical bus arm and the ring resonator arm between the second directional coupler and the third directional coupler; and a tuning mechanism, wherein portions of the optical bus arm and the ring resonator arm traversing the first directional coupler, the first tuner, the second directional coupler, the second tuner and the third directional coupler are symmetrical, and wherein tuning on opposite arms between successive pairs of the first, the second, and the third couplers enables the apparatus to provide dispersion compensation with limited amplitude distortion when the first, second and third directional couplers have a wide range of coupling coefficients.