Multimode optical demultiplexer for DWDM with liquid crystal enabled functionalities

Abstract

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-mum 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 1- and 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 similar to10 and similar to70 ms, respectively. The outputs of the channels are equalized to -65 dBm. The variation between different channels reduced from similar to10 dB to less than 0.5 dB.