We describe a technique for a phase-stepping interferometer based on programmable binary phase holograms, particularly useful for optical testing of aspheric or free-form surfaces. It is well-known that binary holograms can be used to generate reference surfaces for interferometry, but a major problem is that cross talk from higher diffraction orders and aliasing can reduce the fidelity of the system. Here, we propose a new encoding technique which improves the accuracy of the technique and demonstrate its implementation using a binary liquid crystal spatial light modulator.
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| http://dx.doi.org/10.1364/OL.36.002357 | DOI Listing |
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