| 摘要 |
Demodulation of pulse position modulated optical signals is provided by a pair of coherent wavelength converters coupled to an optical correlator. A continuous wave optical source is fed into each coherent wavelength converter. Non-linear optical loop mirrors may be used to implement the coherent wavelength converters. One converter is controlled by an optical pulse position modulated signal, while the other converter is controlled by an optical clock signal that is synchronized to the pulse position modulated signal. Each converter produces an elongated top-hat optical pulse at the frequency of the continuous wave optical source. The optical correlator cross-correlates the outputs of the coherent wavelength converters to produce an output that is proportional to the time offset between a pulse position modulated pulse and its corresponding clock pulse.
|
