High-linearity 208-MS/s photonic analog-to-digital converter using 1-to-4 optical time-division demultiplexers

This letter describes a demonstration of a photonic analog-to-digital converter operating at 208 MS/s and utilizing phase-encoded optical sampling to achieve an 87-dB two-tone third-order intermodulation-free dynamic range. A pair of LiNbO/sub 3/ 1-to-4 optical time-division demultiplexers with >35-dB channel extinction distribute the 30-ps sampling pulses to an array of photonic integrate-and-reset circuits followed by 12-b 52-MS/s electronic quantizers. Interleaving spurs due to temporal crosstalk currently limit the overall spur-free dynamic range to 65 dB.