High resolution displacement detection with speckles : accuracy limits in linear displacement speckle metrology

摘要

We propose a simple measurement setup in reflection and a movement evaluation procedure based on a two dimensional recording of subjective speckle images. Averaging of cross correlation functions is used to determine translations. We show experimentally a 10 nm precision on a 50 μm measurement range with respect to systematical errors. An image library is shown to extend the range of measurements. Limitations are given and documented improvements are predicted to result in accuracy better than 5 nm over a range of 150 μm.