| 摘要 |
An apparatus for stabilizing optical interferometers utilized in an all analog to digital converter using an additional optical signal that differs in wavelength by a factor of two from the wavelength used for the analog to digital conversion is disclosed. The optical interferometers have an optical path length that is tunable. They develop a first interference pattern from the additional optical signal when the optical path length is a prescribed value. The interferometers develop a second interference pattern from the additional optical signal when the optical path length is not the prescribed value. Optoelectronic detectors are responsive to the optical interference pattern generated by the additional optical signal and develop electronic feedback signals when the first interference patterns are not present. Accordingly, feedback circuits produce the optical path length adjustment drive signals, which serve to change the optical path lengths until each interferometer reaches the prescribed value, thereby tuning the optical interferometers. Each tuned interferometer then generates the appropriate optical output from the original optical signal that is made to very in wavelength in accordance to the amplitude of an analog signal so as to produce the appropriate data bit in a corresponding digital word.
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