US 12,295,266 B2
Photosensor, sensor unit, and object detection apparatus using photosensor
Tadaaki Nagao, Ibaraki (JP); and Duy Thang Dao, Ibaraki (JP)
Assigned to NATIONAL INSTITUTE FOR MATERIALS SCIENCE, Ibaraki (JP)
Appl. No. 17/631,147
Filed by NATIONAL INSTITUTE FOR MATERIALS SCIENCE, Ibaraki (JP)
PCT Filed Jul. 30, 2020, PCT No. PCT/JP2020/029266
§ 371(c)(1), (2) Date Jan. 28, 2022,
PCT Pub. No. WO2021/024909, PCT Pub. Date Feb. 11, 2021.
Claims priority of application No. 2019-142927 (JP), filed on Aug. 2, 2019.
Prior Publication US 2022/0271211 A1, Aug. 25, 2022
Int. Cl. H10N 15/10 (2023.01); G01J 5/20 (2006.01); H10N 19/00 (2023.01)
CPC H10N 15/15 (2023.02) [G01J 5/20 (2013.01); H10N 19/00 (2023.02)] 19 Claims
OG exemplary drawing
 
1. A photosensor which is a sensor capable of detecting light, the photosensor comprising:
an absorber having an entire surface formed of only one of a metal and a dielectric and configured to absorb incident light; and
means for detecting heat generated by absorption of light by the absorber, wherein the absorber absorbs light that is perpendicularly incident on a surface of the absorber and has a same wavelength as a resonance wavelength of the absorber,
the surface of the absorber includes a plurality of raised portions that are raised,
the surface of the absorber has a periodic structure in which the plurality of raised portions are arranged at a predetermined period such that a one-dimensional or two-dimensional lattice pattern is formed,
in the one-dimensional lattice pattern,
each of the plurality of raised portions is formed in an elongated manner and is arranged at a first period along a predetermined direction so as to be parallel to each other,
widths of the raised portions are 0.3 to 0.7 times the first period,
thicknesses of the raised portions are 0.05 to 0.2 times the first period,
in the two-dimensional lattice pattern,
each of the plurality of raised portions is arranged at a second period so as to be set out in a grid,
widths of the raised portions are 0.3 to 0.7 times the second period,
thicknesses of the raised portions are 0.05 to 0.2 times the second period, and
each of a plurality of modes of surface plasmon polaritons or surface phonon polaritons excited by a surface parallel component of light incident on the absorber and a momentum obtained from the lattice pattern and propagating over the surface of the absorber is in a degenerate state when the light incident on the absorber is incident perpendicularly to the surface and a wavelength is the resonance wavelength.