Patent Number: 6,434,294

Title: Photonic local oscillator signal generator and method for generating alocal oscillator signal

Abstract: The present invention provides a photonic local oscillator signalgenerator. The generator includes a plurality of waveguides fabricated ina single substrate. The waveguides are fabricated with a lateralseparation that enables an evanescent tail of an optical mode fieldgenerated in one waveguide to overlap with an evanescent tail of anoptical mode field generated in an adjacent waveguide. The overlap of theevanescent tails produce cross-coupling between the laser light generatedin the adjacent waveguides. The generator uses a common pumping element topump laser cavities of both of the waveguides. The use of a common pumpingelement and the cross-coupling produces phase locking between the laserlight generated in the plurality of waveguides. As a result of the phaselocking, mutual optical coherence between the laser light is achieved. Themutual optical coherence provides an interference signal uponphotodetection. This interference signal is the offset between the centerfrequency of the laser light produced in the adjacent waveguides andserves as the local oscillator signal.

Inventors: Gallo; John T. (Lansdale, PA)


International Classification: G02B 6/12 (20060101); G02B 006/34 ()

Expiration Date: 08/13/2014