Frequency stabilization of FDM optical signals using an electronic counter

A new scheme is demonstrated for the frequency stabilization of FDM optical signals. This scheme uses an electronic counter to count signals detected by a scanning Fabry-Perot interferometer, instead of an A/D converter. The frequency measurement accuracy is within 50 MHz, and the frequency stability is within /spl plusmn/200 MHz over 50 hours. Using this scheme, it is possible to stabilize, with high accuracy, the frequencies of FDM carriers with unequal spacings.<
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