Optical interferometer measurement apparatus and method

摘要

Method and apparatus for realizing unusually sensitive and stable interferometric measurement capabilities. The apparatus comprises an optical interferometer with at least two optical outputs, the ratio of whose intensities can vary with a tuning parameter; and at least one detector, each of which is optically connected to the interferometer, and producing in aggregate at least two linearly-independent signals that depend on the light intensity and the tuning parameter, which are combined to produce a first measurement whose sensitivity to light intensity changes is substantially smaller than that of either of the two linearly-independent signals, and a second measurement whose sensitivity to the tuning parameter is substantially smaller than that of either of the two linearly-independent signals.