We propose the use of a new precision monitoring technique based on speckle analysis (SuPreMe). This technique only requires three parts: a laser, a weak optical diffuser (e.g. unpolished metallic surface) and a camera, all elements widely available at a low cost, while allowing absolute position estimation.
The technique relies on the emergence of rings in the power spectrum density of the collected speckle intensity, related to Talbot distance. Using simulation and prior experimental data, we are demonstrating the viability of the technique, showing for example that it is possible to extract absolute displacement measurement of 100 μm with a precision range of 7 nm-rms.
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