OPTICAL SOURCE WITH FREQUENCY LOCKED TO AN IN-FIBEOPTICAL SOURCE WITH FREQUENCY LOCKED TO AN IN-FIBER GRATING RESONATOR R GRATING RESONATOR

摘要

A frequency stabilized optical signal source is provided. A laser produces an optical carrier at a wavelength .lambda.. Feedback is provided to adjust the wavelength .lambda.. In order to provide the feedback, a portion of the optical carrier is modulated by a periodic reference signal. An optical fiber with an in-fiber resonator is coupled to receive the modulated optical carrier. The resonator effects a phase and/or amplitude change between the modulated optical carrier and a sideband thereof at a resonant frequency of the resonator. The phase or amplitude change is detected and used to adjust the laser wavelength. In a preferred embodiment, a moire grating having a single resonant frequency is used as the in-fiber resonator. The feedback scheme can lock either to the carrier frequency itself, or to a selected sideband of the modulated optical carrier.