| 摘要 |
PURPOSE:To attain to enhance magnification by enabling the use of a high magnification objective lens having a rear side focus position therein, by providing a relay lens for relaying diffracted beam formed into an image by an objective lens to again form the same into an image. CONSTITUTION:Laser beam from a laser beam source 12 is converted to parallel beam by a collimator lens 13 to irradiate a regular pattern 11. When the regular pattern is irradiated with parallel beam, a diffraction phenomenon is generated and diffracted beam transmitted through the regular pattern 11 is formed into an image as a diffraction image, that is, a Forier conversion image by an objective lens 14. Because this image is formed to the rear side focus surface (f) in the objective lens 14, diffracted beam is relayed by a relay lens 15 and again formed into an image on a space frequency filter 16 to detect the flaw part of the regular pattern 11. |
