A novel speckle technique, subfeature speckle interferometry, is introduced that relies on the amplitude interference of two independent speckle patterns, originating from coherent illumination, by use of an optical system that produces interferometric quality interference fringes on a scale comparable with the speckle correlation length. Examples are given for in-plane translation, sample tilt, and temperature measurement (strain). A temperature measurement accuracy σ = 0.92 °C is realized. In contrast to traditional full-field speckle cross-correlation techniques, this technique requires only a small number of detector elements with minimal signal processing and is compatible with many real-time sensor applications.
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