| 摘要 |
PROBLEM TO BE SOLVED: To obtain the optical device that the numerical aperture of an optical system is simply and electrically switched without significantly reducing the optical utilization efficiency of the system and an ultraresolution phenomenon is simply made possible electrically. SOLUTION: The device consists of a laser light source 101, a spatial optical modulation element 104, which modulates the laser light beams emitted from the source 101, and a converging optical system 109 which converges the luminous flux modulated by the element 104. The element 104 is at least constituted of a part which functions as a diffraction optical element, and a part which functions as a phase modulation element. The functions of the diffraction optical element and the phase modulation element are controlled by electric signals. |
