An Investigation on Spatial Dimension Multiplexing/Demultiplexing for SDM Systems

With the emergence of new Internet applications and the development of 5G, Internet of Things (IoT) and big data, the demand for communication rate and capacity is growing at a high speed. Optical fiber communication technology has the advantages of high-speed, large capacity, and low power consumption, which has formed a rapid development situation. Space Division Multiplexing (SDM) technology has been introduced to further improve the transmission capacity and bandwidth of optical communication networks to meet the communication requirements of new applications. SDM can be implemented in optical fibers and on-chip integrated waveguides, and the key technology to realize SDM is the spatial channel multiplexing and demultiplexing. In this paper, the basic principles and implementation of SDM multiplexer and demultiplexer for fiber and integrated waveguide-based SDM systems are investigated. The technical methods of these SDM multiplexer and demultiplexer are analyzed and compared in detail. At the same time, the development trend and prospects of future SDM multiplexer and demultiplexer are discussed.