| 摘要 |
1,128,075. Optical apparatus. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N.V. April 27, 1966 [April 29, 1965], No.18449/66. Heading G2J. Light from a helium neon or ruby laser 12 is brought to a point focus 11 by lenses 13, 14 through a circular aperture 15 in an opaque plate 16, and then falls on a collimating mirror 10 from which it is reflected on to an object replica 20. The replica 20 consists of an optically flat reflective surface having a copy of e.g. a seismic record, in relief thereon. The light is diffracted by the relief pattern and is reflected on to an imaging mirror 28 which causes parallel light rays striking its surface to converge to points in its focal plane and thereby form the Fraunhofer diffraction pattern or Fourier transform of the spatial structure of the replica 20. An apertured opaque plate 29 is provided in the focal plane of the mirror 28 and light rays passing through the aperture are re-imaged and observed through a microscope. The diffracted light from the replica 20 is selectively filtered by means of filters 36, 37 in the focal plane of the mirror 28. |
