| QUARTET TECHNOLOGY |
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QUARTET combines the advantages of homodyne interferometry and multidetector ability. The beam reflected by the sample rough surface has many speckle. The multi-speckled beam (signal beam) is combined with the reference beam (Local oscillator) using a beam combiner. Each detector collects few speckle and delivers an homodyne signal. |
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Each homodyne signal is processed in parallel using a patented signal processing architecture, based on "random quadrature" demodulation scheme (taking advantage of the random phase distribution inherent to speckle light). The detectors produce a time-varying analog voltage that is proportional to the rectified instantaneous surface displacement at ultrasonic frequencies. |
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For more details, please check the paper from QNDE 2005 in the resources page. |
