Patent ID: 7680416

Claim:
A wavelength division multiplexed-passive optical network comprising: an optical line terminal for generating downstream optical signals of discrete wavelengths and receiving upstream optical signals of discrete wavelengths; a remote node, coupled to the optical line terminal via a first optical fiber, including a wavelength division unit configured to reflect a given wavelength, the wavelength division unit including: a waveguide grating router coupled at least to a second optical fiber, and a plurality of Bragg gratings provided between the waveguide grating router and the second optical fiber or integrally formed in the waveguide grating router; and a plurality of optical network units coupled to the remote node via the second optical fiber, each optical network unit being associated with one of the Bragg gratings and including an optical source configured to oscillate in a multimode, the optical source being configured to be self injection locked to oscillate in a single mode selected from the multimode when the optical source receives the given wavelength reflected from the remote node, a modulator to modulate an upstream optical signal in the single mode output by the optical source for transmission to the remote node via a third optical fiber that is different than the second optical fiber.