Passive Optical Networks

each colorless ONU is nonspecific and is determined by the filtering properties of

the AWG in the remote node or the wavelength of an injection/seeding light into

the ONU. Directly modulated broadband optical sources such as LEDs, which

are spectrally sliced at the AWG in the remote node, have been proposed as one

form of colorless ONUs. Due to inherently low modulation speeds of these

earlier solutions, alternative solutions based on injection-locked FP-LDs and

wavelength-seeded RSOAs have been proposed. The emission wavelength of an

injection-locked FP-LD or a wavelength-seeded RSOA follows that of the seed-

ing light, which originates from a narrowband slice of light from a broadband

optical source located at the CO. More recently, schemes that ...