Tunable chromatic dispersion compensators using MEMS Gires-Tournois interferometers

In this paper, we report on a FIR (finite impulse response) dispersion compensator made using optical MEMS (micro-electro-mechanical systems) technology. An array of micromirrors is used in a Gires-Tournois (GT) interferometer to obtain the desired dispersion value of the device. This type of device had earlier been shown to function as an optical WDM interleaver/deinterleaver. The proposed device has a periodic transfer function in the frequency domain with a well-defined free spectral range (FSR). Because of the large number of channels in dense WDM systems, periodic filters are advantageous to avoid the need for unique filters for each WDM channel.