| 摘要 |
PROBLEM TO BE SOLVED: To perform the switching of the number of apertures, and the switching of normal resolution and super resolution by using one phase plate and a common optical system. SOLUTION: Linearly polarized light 31 in a prescribed direction (0 deg.) from a light source 20 is set as parallel rays of light 32 with a collimator lens 40. The space polarization modulation device 10 makes the circular area 12a of the central part of a birefringent medium showing photoinduced double refractivity a 1/2 wavelength plate in the direction at 0 deg., and makes an orbicular zone 12b surrounding the circular area 12a a 1/2 wavelength plate in the direction at 45 deg.. Thereby, a circular portion 33a and an orbicular zone portion 33b of light 33 which passed the space polarization modulation device 10 orthogonalize polarized light mutually. When placing a polarized light sensing element 60 between a converging optical system 50 and a converging point 70 and making the direction of the transmission axis at 0 deg., the diameter of an effective entrance pupil becomes small, when making it at 45 deg., the diameter becomes the original diameter of light flux, when making it at 90 deg., a super resolution spot is obtained at the converging point 70, and when making it at 135 deg., a super resolution effect by the phase shift method is obtained. |
