Optical element, illumination device, measurement apparatus, photomask, exposure method, and device manufacturing method

摘要

An optical element includes: an incident surface irradiated with irradiation light; an emission surface of which at least a part faces a direction opposite to the incident surface; and a metal film having a hole to connect the incident surface and emission surface. The incident surface includes a first surface, disposed around an end of the hole on the incident surface side and having an inner edge connected to an inner surface of the hole, and a second surface disposed around the first surface forming a discontinuous portion between the second surface and an outer edge of the first surface. The distance between the inner and outer edges is determined by a wavelength of surface plasmons such that an intensity of light is increased due to interference between surface plasmons, excited at the inner edge by the irradiation light, and surface plasmons traveling from the discontinuous portion.

主权项

1. An optical element comprising:
an incident surface that is irradiated with irradiation light; an emission surface of which at least a part faces a direction opposite to the incident surface; and a metal film that has a hole formed to connect the incident surface and the emission surface; wherein the incident surface includes a first surface, which is disposed around an end of the hole on the incident surface side and has an inner edge connected to an inner surface of the hole, and a second surface which is disposed around the first surface and forms a discontinuous portion between the second surface and an outer edge of the first surface; a distance between the inner edge and the outer edge is determined depending on a wavelength of surface plasmons such that an intensity of light, which is emitted from the hole to the emission surface side, is increased due to interference between surface plasmons, which are excited at the inner edge due to the irradiation of the irradiation light and travel toward the hole, and surface plasmons which travel from the discontinuous portion toward the hole; the inner edge includes a first corner which is formed by the first surface and the inner surface of the hole; and the discontinuous portion includes a second corner which is formed by the first surface and the second surface.