Optical heterodyne detection technique for densely multiplexed millimeter-wave-band radio-on-fiber systems

Even in millimeter-wave-band (mm-wave-band) radio-on-fiber (ROF) systems, wavelength-division multiplexing (WDM) combined with subcarrier multiplexing (SCM) is a practical and attractive way to increase the channel capacity in existing optical-frequency-interleaved fibers. In this paper, we propose a channel selection scheme for interleaved dense WDM/SCM mm-wave-band ROF signals that use optical heterodyne detection with dual-mode local light. The principle underlying this scheme is explained theoretically, and channel selection of the DWDM/SCM ROF signal after transmission over a 25-km-long standard single-mode optical fiber has been experimentally demonstrated.