Patent ID: 7139485

Claim:
A method for channel selective power control of a wavelength division multiplexed optical signal propagating in an optical fiber, the method including the steps of: selecting at least one channel within said optical signal having higher than a desired power level; establishing a resonance to the selected channel, the resonance providing a selection region where said selected channel has a substantially increased power density relative to channels out of resonance; and attenuating said selected channel a desired amount by adjusting the properties of said selection region, wherein the step of establishing a resonance comprises the sub-steps of: providing an external resonator, which is defined by a first and a second mirror, said first and said second mirror being provided outside and on opposite sides of the optical fiber; and deflecting light between the optical fiber and the external resonator, said deflecting being effected by a blazed phase grating provided in a core of said optical fiber.