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