| 摘要 |
PROBLEM TO BE SOLVED: To improve generation efficiency of abnormal light in an optical element using a metal structure.SOLUTION: An optical element 100 comprises a first metal structural layer 2 and a second metal structural layer 4 which are constituted of a plurality of metal structures having the size smaller than an incident wavelength being a wavelength of incident light, and a dielectric layer 3 disposed between the first and second metal structural layers. A plurality of metal structures 5(5a-5h) constituting the respective first and second metal structural layers include metal structures having different shape from each other. When a distance between the first and second metal structural layers is defined as dz, the incident wavelength as λ, a refraction index of the incident wavelength of the dielectric layer as n, and N as an integer of 0 or more, a condition of λ(2 N+0.5)/(4n)≤dz≤λ(2 N+1.5)/(4n) is satisfied.SELECTED DRAWING: Figure 1 |
