Large-channel-count WDM control devices

Summary form only given. There now exist commercial wavelength-division multiplexing (WDM) systems with at least 80 wavelengths. There are many approaches to designing optical control devices, such as wavelength add-drops, wavelength selective cross connects, and dynamic equalizers, to handle so many channels. One approach is to use devices that act on only one or a few channels at a time and leave the other untouched, such as tunable Bragg gratings. Another approach is to use an optical interleaver, which separates out every other channel, resulting in multiple streams with lower channel counts, allowing one to use small (but multiple) optical devices to control all the channels. Here we focus on a third approach, which should be the most flexible and inexpensive: handling all the channels in a single, compact device.