Integrated-optic interferometer position sensor

A fully integrated interferometer position/displacement sensor with direction-discrimination capability is discussed. The device is constructed by integrating three kinds of grating components and a pair of photodiodes in a glass waveguide on a silicon substrate and by butt-coupling a single-mode laser diode. Interference signals corresponding to mirror movement were obtained experimentally over a 15-cm range with a 0.39- mu m modulation period.<
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