Method and Apparatus for Evaluating the Optical Spatial Response Characteristics of Objects.
Patent Application, Filed 8 Jul 92,
DEPARTMENT OF THE NAVY WASHINGTON DC
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An apparatus and method for optically testing an object, such as an optical detector whose pixels are an array of optically sensitive charged coupled devices. Two mutually coherent beams of light are interfered on the object to form an interference fringe pattern of sinusoidally varying intensity of preselected spatial frequency. The objects response at this spatial frequency is used to determine one point of the objects modulation transfer function at that frequency. This is preferably done by using the devices output to infer the coherence function of the fringe pattern, taking the Fourier transform of the coherence function, and determining the amplitude of the function at the spatial frequency of the fringe pattern. The process can be repeated for different spatial frequencies until one determines the entire modulation transfer function.
- Theoretical Mathematics