Fourier Plane Image Research Articles

Photorefractive materials and their applications in optical image processing

A brief review of a band transport model for the photorefractive effect is given. Distinction is made between the influence of intrinsic material dependent parameters and externally controlled parameters on the form of the optical nonlinearity. These considerations are made in the context of dynamic holographic optical processing applications. Examples of adaptive optical and Fourier-plane image processing using four-wave mixing in photorefractive bismuth silicon oxide crystals are discussed. Critical assessment is then made of the use of photorefractive materials in image cross-correlation schemes.

Specularity Measurements For Solar Materials

A technique using Fourier transform analysis which is suitable for measuring the specularity of solar glass components in the mrad and sub-mrad is discussed and demonstrated. A brief mathematical background as well as illustrative examples are included. A number of methods for image analysis are discussed with particular emphasis given to electronic integrating detectors. Typical Fourier plane image distributions are given for a few common solar utilization materials, and details of the instrument used to produce the images are considered. The limitations and capabilities of various instruments are outlined along with methods for further enhancing the utility and sensitivity of the technique.