| 摘要 |
PURPOSE:To improve the S/N, by using a BiSiO crystal to constitute a space modulating element of an optical correlative processor which discriminates a desired target image out of the pictures supplied from an image pickup device by means of a holography matching filter. CONSTITUTION:The picture of a CRT 1 is formed on a space modulating element 4 via a lens 2 and a dichroic mirror 3. The coherent light 5 is collimated 6 to irradiate the element 4, to detect transmitted light 8 and to convert into a coherent picture. The coherent picture undergoes a Fourier conversion through a lens 9, to provide a hologram storage element 10. The reference signal beams divided into two parts by a half mirror 7 are irradiated to the element 10 via a mirror 11 and an aperature 12 to be recorded as holograms and to form a matching filter. The element 4 is made of a Bi12SiO20 crystal. As a result, the time during which a target image is written to the element 4 during production of the matching filter is coincident with the writing time that is decided by the repeating frequency used for a high-speed correlative process. This improves the S/N of the correlative signal light. |
