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Acquisition and Analysis Software for an Enhanced Bandwidth Phase Measuring Interferometer



P Sullivan


The aim of the project is to investigate the potential of expanding the instrument measurement bandwidth of a traditional phase measurement interferometer (PMI) system using a comparatively simple optical / software modification. This would offer the benefit to users of gaining increased measurement bandwidth within a single measurement set-up. The principle of operation of the device is to measure the scratches and digs (or so-called cosmetics) which constitute a high frequency roughness component on the test optic; the quantified scratch and dig information is then combined with the traditional figure (low frequency) measurement obtained from the conventional PMI. Here at NIST, we have developed software to acquire and analyze image data obtained from the CCD camera in the Enhanced Bandwidth PMI (EBPMI). The software integrates the vendor-provided (DIPIX) digital signal processing (DSP) and graphic signal processing (GSP) frame grabbing routines and the analysis capabilities of a commercial matrix analysis package (MATLAB including the Image Processing and Signal Processing Toolboxes). This document describes the design and construction of a bread boarded set-up of the test instrument. It includes some preliminary test measurements demonstrating the functionality of the system. Particular emphasis is given to the description of the software integration protocol and sample analysis capabilities.
Laser Focus World


image analysis, interferometer, phase measurement interferometer (PMI), scatter


Sullivan, P. (1995), Acquisition and Analysis Software for an Enhanced Bandwidth Phase Measuring Interferometer, Laser Focus World (Accessed April 23, 2024)
Created January 1, 1995, Updated February 19, 2017