Improvement of the extinction ratio of a Mach Zehnder interferometer filter

Abstract A novel structure of a Mach–Zehnder interferometer filter is proposed and demonstrated. The interferometer is structured by adding an optical isolator to the two outputs of the conventional Mach–Zehnder interferometer. The characteristic of the transmission spectrum is studied theoretically and experimentally. The extinction ratio of the novel interferometer filter is improved greatly in comparison with that of a conventional Mach–Zehnder interferometer filter with the same parameters. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 420–422, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20323