Beat-detect OTDM demultiplexer

We propose a novel ultrafast (instantaneous response), low-power, and simple demultiplexer for optical time-division multiplexed signals. It requires no ultrafast optical devices such as all-optical gates or electroabsorption modulators. Only a power combiner and a dispersive medium are required as optical components, thus making the system very simple. Furthermore, the separation of control pulses is not required, which also helps to simplify the system. A design optimization in terms of the signal-to-noise ratio was performed, and equations that provide design parameters were derived. The effect of the wavelength fluctuation and the timing jitter of signal pulses were evaluated based on a numerical analysis, which indicated that this demultiplexer shows a small bit error rate (<10^-10), even under a large wavelength fluctuation (~7.2 nm, 43% of the pulse spectral width) or a large timing jitter (~0.45 ps, 18% of the signal period) in the case of demultiplexing from 400 to 6.67 GHz. Demultiplexing of pulse trains with 2.5-ps separation (corresponding to 400-GHz repetition) was experimentally demonstrated