We present a sensitivity analysis and performance evaluation of a six-degree-of-freedom measurement system that uses a diffraction grating as a cooperative target. To design the measurement system, we require a theoretical analysis of performance, such as sensitivity of each sensing direction. The intensity distributions of the diffracted beams are calculated with the scalar diffraction theory and sensitivity of the measurement system is analyzed against the variations of design parameter values. Using the results of sensitivity analysis, we design the measurement system and evaluate its performance with resolution, measurement error, and crosstalk. The resolution is less than 0.2 μm in translation and 0.5 arcsec in rotation. In experiments, measurement error and crosstalk between sensing channels are within ±0.5 μm in translation and ±2 arcsec in rotation.
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