Wavelength selective optical element for reflecting light

摘要

An optical element is provided includes an optical layer having a flat incident surface on which light is incident and a wavelength-selective reflective layer disposed in the optical layer. Of light incident on the incident surface at an incident angle (θ, φ), the optical element selectively directionally reflects light in at least one specific wavelength range in at least one direction other than a specular reflection direction (−θ, φ+180°) while transmitting light in at least one wavelength range other than the specific wavelength range, and is transparent to light in at least one wavelength range other than the specific wavelength range.

主权项

1. An optical element for transmitting and reflecting light, the optical element comprising:
an optical layer having a flat first surface upon which the light is incident; and a wavelength-selective reflective layer disposed in the optical layer; wherein: θ is the angle of light incident on the first surface or reflected light exiting through the first surface with respect to a normal of the first surface; and φ is the angle of a component of the light incident on the first surface or the reflected light projected on the first surface with respect to a specific line in the first surface, of light incident on the first surface at an incident angle (θ, φ), the optical element selectively directionally reflects the light in at least one specific wavelength range in at least one direction other than a specular reflection direction (−θ, φ+180°) while transmitting light in at least one wavelength range other than the specific wavelength range, and is transparent to light in at least one wavelength range other than the specific wavelength range, and an intensity of the directionally reflected light in the at least one direction other than the specular reflection direction (−θ, φ+180°) is higher than an intensity of light reflected in the specular reflection direction (−θ, φ+180°).