| 摘要 |
Optical correlator for comparing a test sample with a standard object in which a diffractive image of the sample is projected on a holographic filter by a beam of coherent light. The light beam being diffracted by the filter is subsequently conveyed through an apertured diaphragm into a light-measuring apparatus generating an electrical signal proportionate to the intensity of the received light. An auxiliary filter is positioned either forwardly or rearwardly of the holographic filter, and is either a black-white or phase-reversing filter transmitting either one or both halves, respectively, of each of the diffraction orders generated by the standard object. |
