Eight-Channel Optical Add-Drop Multiplexer With Cascaded Parent-Sub Microring Resonators

An eight-channel integrated optical add-drop multiplexer with cascaded parent-sub microring resonators is experimentally demonstrated on a silicon-on-insulator (SOI) substrate. Through thermal tuning, each channel can be independently switched between the adding and dropping states. The measured thermal tuning efficiency is 0.15 nm/mW. Typically, all eight channels can be multiplexed and demultiplexed with a 2.6-dB drop loss, a 0.36-nm bandwidth (> 40 GHz), and a -20-dB channel crosstalk. Moreover, the scheme to increase the number of operating channels is also discussed.