Optical demultiplexing of millimeter-wave subcarriers for wireless channel distribution employing dual wavelength FBGs

An optical mm-wave demultiplexer is presented. Double sideband modulation with suppressed optical carrier and filtering properties of dual overwritten fiber Bragg gratings are the fundamentals for optical demultiplexing of mm-wave radio-on-fiber signals: using a single optical carrier, Millimeter-wave signals of 20 and 40 GHz frequencies carrying independent data are created, transmitted over fiber, demultiplexed and wireless distributed to be detected and data recovered in a mobile unit. Double sideband modulation with suppressed optical carrier yields no power penalty due to chromatic dispersion, while the filtering properties of the dual overwritten fiber Bragg gratings allow less than −40 dB electrical power interchannel leakage. Independent 2.5 Gb/s On-Off-keyed data have been successfully transmitted through the 20 and 40 GHz channels.