Multi-rate asynchronous sampling of bandwidth-limited signals
  We demonstrate experimentally an optical system for under-sampling several bandwidth limited signals with carrier frequencies that are not known apriori that can be located anywhere within a very broad frequency region between 0-18 GHz. The system is based on under-sampling asynchronously at three different sampling rates. The pulses required for the under-sampling are generated by a combination of an electrical comb generator and an electro-absorption modulator. To reduce loss and improve performance the implementation of the optical system is based on a wavelength division multiplexing technique. An accurate reconstruction of both the phase and the amplitude of the signals was obtained when two chirped signals generated simultaneously were sampled. 
Alfred Feldster, Yuval P. Shapira, Moshe Horowitz, Amir Rosenthal,   Shlomo Zach, and Lea Singer