Patent ID: 7405814
Filing Date: 2008-07-29
Classification: G01B,G01H

Abstract:
1. An apparatus for capturing measurement information, comprising: a beam splitter for splitting a laser beam into a reference beam and a test beam; an acousto-optic modulator (AOM) for spatially separating and modulating the test beam into a subaperture array of distinct frequency-shifted beams, each obtaining a unique frequency shift, for applying across a measured element, the AOM driven by a drive frequency array of signal inputs; a beam expander for spatially dispersing the reference beam to at least match the subaperture array of the distinct frequency-shifted beams; a beam combiner for interfering the subaperture array of the distinct frequency-shifted beams applied to the measured element with the spatially dispersed reference beam; optics for directing the interfered subaperture array of the distinct frequency-shifted beams; a photodetector for receiving the interfered subaperture array of the distinct frequency-shifted beams to produce an electrical signal from the photodetector carrying the measurement information of the measured element; and a processor for comparing an array of reference optical path differences derived from the array of signal inputs with the electrical signal from the photodetector to determine the measurement information of the measured element.