1 June 1984 Optical Transversal Processor For Notch Filtering
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Optical Engineering, 23(3), (1984). doi:10.1117/12.7973285
A frequency domain implementation of an optical transversal processor has been described previously. Since this system uses Bragg cells both as the delay line and as the accumulators that provide the tap weights, a key question concerns the effect the finite integration times have on the perfor-mance of the system. Computer programs were written to simulate an adaptive notch filtering application; the measure of performance is the correlation coefficient for the residual signal and the desired received signal. The correlation coefficient was increased significantly by tapering the accumulators so that the readaptation phenomena caused by large values leaving the accumulator are minimized. Several examples of the performance are given as a function of the number of taps, the length and degree of taper of the accumulator, the feedback gain, and the number of iterations. The results show that a finite accumulator is not a serious drawback, particularly for those applications in which the system must operate in a rapidly changing environment. The performance of the system then approaches that of one having an infinite accumulator with the gain adjusted to give equivalent tracking performance.
A. Vander Lugt, "Optical Transversal Processor For Notch Filtering," Optical Engineering 23(3), (1 June 1984). https://doi.org/10.1117/12.7973285

Digital filtering

Optical filters

Bragg cells

Computer simulations

Electronic filtering

Pollution control



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