| 摘要 |
Method and apparatus for generating a plurality of separate and distinct signal beams of mutually coherent radiation. The signal beams, which are of substantially equal intensity, are produced as the result of interference generated by directing a beam of coherent radiation at a radiation-impeding medium having a plurality of regularly spaced and substantially identical zones of variable impedance (e.g., a plurality of very small cylindrical lenses or mirrors). The invention is illustrated as it might be used in apparatus for recording data in the form of a plurality of diffraction gratings of individually unique spatial frequencies effectively superimposed one upon another, the individual gratings being produced as the result of further interference patterns created by the intersection of a reference beam and each of the plurality of signal beams.
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