Optical element, image sensor and imaging device for wavwlength-dependent focusing of visible and near-infrared light
An optical element includes a transparent layer for covering a plurality of pixels each including a photoelectric conversion element, and a plurality of structure bodies arranged on the transparent layer or in the transparent layer in a plane direction of the transparent layer. The plurality of structure bodies is arranged in such a manner that, among incident light, first light having a wavelength in a near-infrared light region is condensed on a first pixel among the plurality of pixels, and light of a second color having a wavelength in a region outside the near-infrared light region is condensed on a second pixel.
1 . An optical element, comprising:
a transparent layer for covering a plurality of pixels each including a photoelectric conversion element; and
a plurality of structure bodies arranged on the transparent layer or in the transparent layer in a plane direction of the transparent layer, wherein
the plurality of structure bodies is arranged in such a manner that, among incident light, a first light having a wavelength in a near-infrared wavelength range is condensed on a first pixel among the plurality of pixels, and a second light of a second color having a wavelength outside the near-infrared wavelength range is condensed on a second pixel, and wherein the plurality of structure bodies is arranged to condense, onto a given pixel for a given color, a portion of the incident light having a wavelength range corresponding to the given color and incident on regions that face multiple pixels surrounding the given pixel.
2 . The optical element according to claim 1 , wherein
each of the plurality of structure bodies is a columnar structure body having a refractive index higher than a refractive index of the transparent layer and giving an optical phase delay amount according to a cross-sectional shape to the incident light, and
a cross-sectional shape of the plurality of structure bodies is set according to an optical phase delay amount distribution for achieving light condensation, and the plurality of structure bodies is arranged according to the optical phase delay amount distribution for achieving the light condensation.
3 . The optical element according to claim 1 , wherein a cross-sectional shape of each of the plurality of structure bodies is a four-fold rotationally symmetrical shape.
4 . An imaging element, comprising:
the optical element according to claim 1 ; and
the plurality of pixels covered with the transparent layer.
5 . The imaging element according to claim 4 , further including a filter layer provided between the plurality of pixels and the transparent layer.
6 . The imaging element according to claim 5 , wherein the filter layer is a near-infrared absorption filter provided only on the second pixel.
7 . An imaging device, comprising:
the imaging element according to claim 6 ; and
a signal processing unit configured to generate an image signal on a basis of an electric signal obtained from the imaging element.
8 . An optical element, comprising:
a transparent layer for covering a plurality of pixels, each including a photoelectric conversion element; and
a plurality of structure bodies arranged on the transparent layer or in the transparent layer in a plane direction of the transparent layer, wherein
the plurality of structure bodies outputs a first light that has a wavelength in a near-infrared wavelength range among incident light, and outputs a second light of a second color having a wavelength outside the near-infrared wavelength range among the incident light, wherein the plurality of structure bodies is arranged to condense, onto a given pixel for a given color, a portion of the incident light having a wavelength range corresponding to the given color and incident on regions that face multiple pixels surrounding the given pixel.