Very High Sensitivity Displacement Sensor Based on Resonant Cavities

A new way of sensing displacement for subnanometric applications using RF resonant cavities is presented and experimentally demonstrated on a laboratory prototype. The new sensor physical principle of operation is summarized, and a first working prototype is described and tested. It is shown by experiment that very high and linear sensitivity characteristic curves, in the range of several kilohertz per nanometer, are easily obtainable using this kind of devices, making them serious candidates as alternative and reasonably priced sensors for subnanometric displacement measurement.