| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical inspection apparatus which can surely carry out a filtering process to a scattering light from a measuring object,, and has its efficiency of utilizing light improved. SOLUTION: The scattering light for inspection from a light irradiation device 10 after being diffracted and scattered by the measuring object S is imaged by an imaging lens 20 to an imaging face P2 at an imaging apparatus 40. At this time, the filtering process for emphasizing an image of an abnormal point such as a foreign matter, a defect or the like is carried out, in which a polarization state is modulated in accordance with a periodic pattern structure of the measuring object S by a reflecting type spatial optical modulator 30 arranged near a Fourier face P1, and moreover the polarization state is selected by a polarizing beam splitter 21 and a polarizing plate 22. In inspecting the abnormal point of the measuring object S, the efficiency of utilizing light to the scattering light and a shielding efficiency to light components from the pattern are improved.
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