Ultra-high-density optical multi/demultiplexer using tandem configuration of primary and secondary AWGs

Summary form only given. The most effective way to expand network capacity is to increase the number of WDM channels, and a persistent demand has emerged for a large-scale multiplexer/demultiplexer with a narrow channel spacing that can support the maximum number of channels. We have found a way to extend the channel number beyond 1,000 by using a tandem configuration. This consists of a one l /spl times/ N primary filter and a number of secondary 1 /spl times/ N 10 GHz-spaced arrayed waveguide gratings (AWGs). The primary filter has flat-top passbands whose channel spacing is 1 THz. We connect one secondary AWG to each output port through an optical fiber.