Abstract
Effects of fiber dispersion on the radio-over-fiber (RoF) transmission of a microwave signal are experimentally demonstrated when deep optical modulation is employed. In a previous paper (J. Lightwave Technol., vol. 30, pp. 2625–2632, Aug. 2012), the authors analytically predicted that harmonics of sidebands generated by the nonlinear response of optical modulators would contribute to the cyclic variation of the signal amplitude other than by dispersion-induced fading. To confirm this prediction, we set up an RoF link that transmitted a 16-quadrature amplitude modulation microwave signal, and we observed changes in the constellation map. Experiments were conducted both for optical double-sideband (ODSB) signals and optical single-sideband plus carrier (OSSB+C) signals. In the ODSB case, outer symbols in the constellation map moved slightly outwards as the signal propagated down the fiber. If we eliminated the harmonic sidebands by using an optical filter, the movement was reversed; this was probably due to the residual chirp in the LN modulator. In the OSSB+C case, we observed a similar movement but also a slight phase rotation that depended on the amplitude of the symbol. These observations qualitatively agree with our predictions.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
