60 GHz millimeter-wave generation and transport using stabilized mode-locked laser diode with optical frequency DEMUX switch

A novel optical generation and transport technique of optical frequency division multiplexing (OFDM) mm-wave signals is proposed. A number of mm-wave signals can be simultaneously generated by using a coherent multi-frequency light source and transported over an optical fiber network. The OFDM signals are demultiplexed and distributed to individual microcell zones. Each pair of lightwaves is converted into a mm-wave at the base station by optical self-heterodyning. The key device to the coherent multi-frequency light source is a stabilized mode-locked laser diode (MLLD) combined with a special class of optical frequency demultiplexing (DEMUX) switch. 60 GHz mm-wave generation and the transport over a 40 km-long optical fiber is successfully demonstrated. The 3 dB linewidth of the generated mm-wave as narrow as 0.3 kHz shows an excellent frequency stability of the light source.