Abstract

The next generation fiber optical communication systems can be characterized in three trends: higher speed, better spectrum efficiency and longer transmission reach. To meet the requirement of next generation systems, passive DWDM components must have the following characteristics, low dispersion, small channel spacing, low insertion loss and high isolation. In this paper, we discuss one of the most important passive components: interleaver. Interleavers have been widely used in fiber optical communications systems. Their main functions include mux, demux, optical add/drop and Rayleigh-noise reduction in bi-directional systems. As data rate of fiber optical communication systems increases to 10 Gb/s or higher, chromatic dispersion (CD) of inter-leavers becomes increasingly important. It has been shown that chromatic dispersion of inter-leavers could significantly limit the transmission reach. In this paper, we discuss the origins of chromatic dispersion of interleavers. We present chromatic dispersion of three different types of interleavers. We show that the intrinsic chromatic dispersion of a interleaver quadruples as its channel spacing reduced by half. We further present two effective methods for reducing chromatic dispersion of interleavers. Finally, we present the performance of two 25 GHz flat-top interleavers that meet the stringent requirements of 10 Gb/s applications.

© 2002 Optical Society of America