Realization of first‐order monotonic butterworth‐type low‐pass and high‐pass optical filters: Experimental verification

Abstract

AbstractWe present an experimental implementation of the first‐order monotonic Butterworth‐type low‐pass and high‐pass optical filters, using a coherent all‐zero fiber‐optic filter (AZFOF), as a verification of our previously proposed theory [1]. The filter realization technique shows that the all‐fiber Mach‐Zehnder interferometer (AFMZI) belongs to a special class of the first‐order monotonic Butterworth‐type optical filter. The phase‐modulated AZFOF is shown to be a potential candidate as a tunable optical blocking filter. © 1995 John Wiley & Sons. Inc.