Abstract
Multi-core fibers (MCFs) and few-mode fibers (FMFs) are expected as a good candidate for overcoming
the capacity limit of a current optical communication system. This paper reviews the classification and
recent works of MCFs, FMFs and few-mode multi-core fibers for space division multiplexing
transmission. In addition, design concept and characteristics of a single-mode 37-core fiber, which has
largest core number so far, are presented. Here, tradeoff requirements such as core count, Aeff, inter-core
crosstalk, and cladding diameter are discussed.
