OPTICAL ELEMENT, IMAGE DISPLAY UNIT, AND IMAGING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide an optical element using plasmon resonance which suppresses reflection while maintaining transmission wavelength characteristics.SOLUTION: The optical element comprises a plurality of metal structures 2 two-dimensionally arranged in first and second directions with a cycle smaller than an incident wavelength. Each metal structure includes inclined parts 2b, 2d having cross sections parallel to the first and second directions, the cross sectional areas of which decrease toward a third direction perpendicular to the first and second directions. The inclined parts satisfy a conditional expression of -2&pgr;