| 摘要 |
The microcomputer controlled image processor receives an interference pattern of samples of pairs of transmitted laser beams from a charge couple device (CCD) camera. The present invention then calculates an optical path difference between each pair of beams using: an analog amplifier, an analog-to-digital (A/D) converter, a multiple accumulator controller, a programmable read-only-memory (PROM), a microcomputer, and a random access memory (RAM). The analog amplifier and A/D converter amplify and convert to digital the interference pattern received from the CCD camera. The multiple accumulator controller (MAC) receives the digital camera signal from the A/D converter, and adds correction factors for the non-linearities in the CCD camera. The PROM stores these correction factors, and supplies them to the multiple accumulator controller when needed. The random access memory receives and stores the corrected data from the multiple accumulator controller, and supplies the data to the microcomputer. The microcomputer receives the corrected digital interference pattern from the random access memory, and applies two algorithms to the data to yield estimates of the optical path difference between the two sampled laser beams. The optical path difference (OPD) is a measure of adjustment in the optical path lengths of the two sampled laser beams. When this OPD value is supplied to the laser transmitter, a correcting means can adjust the length of the optical paths of one or both of the sampled laser beams to bring them in phase with each other.
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