High resolution position measurement from dispersed reference interferometry using template matching.

This paper describes a method to extract high resolution position data from a dispersed reference interferometry (DRI) by applying a template matching technique to the acquired spectral interferograms. Calculation of the correlation coefficient between windowed spectral interferograms acquired from the DRI apparatus and a set of numerically calculated template interferograms allows the absolute determination of position with nanometer resolution. Both the operating principle of the DRI apparatus and implementation of the template matching method is presented. Experimental validation of the method is provided through the demonstration of position tracking and an assessment of linearity, repeatability and noise performance.