Optics: measuring and testing – By light interference
Reexamination Certificate
2007-05-29
2007-05-29
Toatley, Jr., Gregory J. (Department: 2877)
Optics: measuring and testing
By light interference
Reexamination Certificate
active
11030596
ABSTRACT:
Techniques and devices for digitally resolving quadrature fringe signals from interferometers such as optical interferometers and interferometer-based sensing devices. In one implementation, two quadrature fringe signals from an interferometer which causes two signals in two signal paths to interfere with each other are sampled to obtain digital data samples from the two quadrature fringe signals. The digital data samples are used to perform a linear least square fitting to establish coefficients for an ellipse traced by the two quadrature fringe signals as a phase difference between the two signal paths changes. A pair of digital data samples are respectively obtained from the two quadrature signals at a given moment and are used to compute a corresponding phase difference between the two signal paths of the interferometer from established coefficients of the ellipse. The coefficient for the ellipse can be updated over time. This digital processing allows for real time processing.
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Berger Jonathan
Dzieciuch Matthew
Parker Robert L.
Zumberge Mark A.
Connolly Patrick
Fish & Richardson P.C.
Toatley , Jr. Gregory J.
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