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A new reflected mode magneto-optic spatial light modulator (R-MOSLM) has been developed for miniature optical correlators and computers. A factor of 4 improvement in pixel switching sensitivity, compared to the conventional transmission mode magneto-optic spatial light modulator, has been achieved by the use of narrower drive lines, and burying the conductor into the film. A factor of 3 higher resolution and a factor of 2 higher optical efficiency have also been achieved by the use of smaller pixels and narrower pixel gaps. The smaller pixels and improved switching sensitivity permit an order of magnitude reduction in optical path length and increase in frame rate, respectively. The progress that has been made in the design of the R-MOSLM, issues concerning its fabrication, a comparison by finite element analysis of field modeling to experimentally determined current requirements to drive individual lines, and some optical characteristics are discussed.

Large, thin-film single domain areas have been observed, in the absence of a bias field, in garnets with magnetization perpendicular to the film plane.1,2 The domain stability in the work by Krumme1 was attributed to a combination of low saturation magnetization and a low Curie temperature. Uchishiba2 relates the stability in his double layer system to appropriate anisotropy fields in one layer compared to the magnetization in the other layer. A more complete model for large domain stability in a bias field free environment is given in this work. Three distinct stability regimes are predicted by the model and all have been observed experimentally. Areas 3.5-cm in diameter have been made into stable single domains. This was achieved in a material showing a zero bias strip width of 4.5 μm. The single domain diameter was, therefore, 7500 times the equilibrium energy domain width. The technique developed and the model have led to a new means for observing magnetic defects. More importantly, it also offers a means for measuring the strength of the defects. Possible applications of the model are also discussed.

The development of an optical correlator system and flight tests to be conducted from a remotely piloted vehicle (RPV) are described. The optical processor is based on laser gyroscope consiruction techniques and relies on 128x128 reflective-mode magnetooptic spatial light modulators for both the input image and spatial filter insertion. The input image is obtained from a visible camera in the nose of the RPV. The processing system will incorporate Kallman's invariant filters. The output of the correlator is through a 128x128 high speed CCD camera. The correlator system also includes image processing and all electronic drivers. The optical package occupies a volume less than 25 in3 while the whole processor package is less than 1 ft3 and weighs less than 40 lbs, and is ruggedized for temperature, shock, and vibration. The RPV, Eglin Air Force Base test range facilities, tower tests, telemetry, and training set acquisition are discussed.

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