310-km FM-Conversion A-RoF-Transmission Experiment Using Chirped Fiber Bragg Gratings

The world’s longest transmission distance for a commercial frequency modulation (FM)-conversion analog-radio over-fiber system exceeds 300 km. This system multiplexes community antenna television /broadcasting satellite / communication satellite video signals with frequencies from 90 MHz to 2.1 GHz, converts them into optical signals, and transmits them from the broadcaster building to customer houses. In the FM-conversion system, dispersion compensating fibers (DCFs) are used to compensate for the chromatic dispersion generated in the transmission optical fiber. However, due to the risk of DCF depletion in the long term, it is necessary to consider alternative dispersion-compensation configuration. Therefore, we propose a chirped fiber Bragg grating (CFBG) dispersion-compensation configuration and conducted an FM-conversion long-distance- transmission experiment using this configuration and evaluated its applicability. We clarified that the carrier-to-noise ratio is improved by arranging CFBGs in front of the transmission fiber, compared with using DCFs.