Multimode optical demultiplexer for DWDM with liquid crystal enabled functionalities

We have developed a liquid-crystal-based multimode optical demultiplexer (DEMUX) with additional functionalities such as switching and power equalization. Demultiplexing 16-channel 100-GHz-spaced signals into a 62.5-μm multimode-fiber array is demonstrated. The central wavelength of each channel is designed according to the International Telecommunication Union grid. Adjacent channel crosstalk is less than -30 dB. The average 1and 3-dB passbands of the DEMUX are 12.5 and 22.5 GHz, respectively. A maximum extinction ratio of 16.2 dB is achieved. Different channels can be switched with rise and fall times of /spl sim/10 and /spl sim/70 ms, respectively. The outputs of the channels are equalized to -65 dBm. The variation between different channels reduced from /spl sim/10 dB to less than 0.5 dB.