CNR enhancement using mach-zehnder filter (MZF) with tunable phase shifter in a digital/RF optical-transmission link

We experimentally demonstrate a digital/RF WDM-link system, which transmits a 1.25-Gb/s digital data stream and 1.8-GHz RF signals over a single-mode fiber, and simultaneously detect the signals using a single photodiode. We propose a novel suppression scheme employing a Mach–Zehnder filter (MZF) to improve the CNR of the RF signal for the case where the digital and RF channels are located close to each other. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 531–533, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20870