| 摘要 |
Provided are an optical device, a detection apparatus, etc., capable of obtaining a sufficiently large enhanced electric field without utilizing coupling between a localized surface plasmon and a propagating surface plasmon. An optical device includes a substrate, a metal layer formed on the substrate, a dielectric layer formed on the metal layer, and multiple metal nanostructures formed on the dielectric layer. When the thickness of the dielectric layer is denoted by d and the polarizability of the metal nanostructures is denoted by α, the following formulae are satisfied: d>α1/3/2 and d>40 nm. |
| 主权项 |
1. A detection apparatus, comprising:
a light source; an optical device on which a light from the light source is incident; and a light detector which detects a light emitted from the optical device, wherein the optical device includes: a substrate; a metal layer formed on the substrate; a dielectric layer formed on the metal layer; and multiple metal nanostructures formed on the dielectric layer, when the thickness of the dielectric layer is denoted by d and the polarizability of the metal nanostructures is denoted by α, the following formulae are satisfied: d>α1/3/2 and d>40 nm, when the excitation wavelength is denoted by λ, the complex permittivity of the dielectric layer is denoted by ∈1, and m denotes a natural number, the thickness d of the dielectric layer is substantially equivalent to mλ/2√∈1, and when the pitch between adjacent metal nanostructures among the multiple metal nanostructures is denoted by P, the length of the metal nanostructure in the pitch arrangement direction is denoted by 2r, the excitation wavelength is denoted by λ, the complex permittivity of the dielectric layer is denoted by ∈1, and the complex permittivity of the metal layer is denoted by ∈2, the following formula is satisfied: 2r<P<λ{(∈1+∈2)/∈1∈2}1/2. |
