Optical filter and spectrometer including sub-wavelength reflector, and electronic apparatus including the spectrometer

Patent metadata

Field	Value
Publication number	US-2020073033-A1
Application number	US-201916437832-A
Country	US
Kind code	A1
Filing date	Jun 11, 2019
Priority date	Aug 31, 2018
Publication date	Mar 5, 2020
Grant date	—

Abstract

An optical filter includes a first reflector including a plurality of first sub-wavelength structures that are two-dimensionally arranged and spaced apart by a first period based on a first rule, and a second reflector provided separate from the first reflector, the second reflector including a plurality of second sub-wavelength structures that are two-dimensionally arranged and spaced apart by a second period based on a second rule.

First claim

What is claimed is:

1 . An optical filter comprising:
a first reflector comprising a plurality of first sub-wavelength structures that are two-dimensionally arranged and spaced apart by a first period based on a first rule; and a second reflector provided separate from the first reflector, the second reflector comprising a plurality of second sub-wavelength structures that are two-dimensionally arranged and spaced apart by a second period based on a second rule.

2 . The optical filter of claim 1 , wherein a refractive index of each of the plurality of first sub-wavelength structures and a refractive index of each of the plurality of second sub-wavelength structures are higher than a refractive index of a peripheral material that surrounds each of the plurality of first sub-wavelength structures and each of the plurality of second sub-wavelength structures, and
wherein an absorption coefficient of each of the plurality of first sub-wavelength structures and an absorption coefficient of each of the plurality of second sub-wavelength structures are lower than an absorption coefficient of the peripheral material.

3 . The optical filter of claim 1 , wherein each of the plurality of first sub-wavelength structures and each of the plurality of second sub-wavelength structures comprise a dielectric material or a semiconductor material.

4 . The optical filter of claim 1 , wherein each of the plurality of first sub-wavelength structures and each of the plurality of second sub-wavelength structures have a cylindrical shape or a regular polyprism shape.

5 . The optical filter of claim 2 , further comprising a substrate having a refractive index that is lower than the refractive index of each of the plurality of first sub-wavelength structures,
wherein the first reflector is provided on the substrate.

6 . The optical filter of claim 5 , further comprising a first material layer having a refractive index that is lower than the refractive index of each of the plurality of first sub-wavelength structures,
wherein the first material layer encapsulates the first reflector.

7 . The optical filter of claim 6 , further comprising a second material layer having a refractive index that is lower than the refractive index of each of the plurality of second sub-wavelength structures,
wherein the second material layer is provided on the first material layer and encapsulates the second reflector.

8 . The optical filter of claim 7 , wherein the first material layer and the second material layer comprise a same material.

9 . The optical filter of claim 1 , wherein the first rule and the second rule are the same.

10 . The optical filter of claim 1 , wherein each of the plurality of first sub-wavelength structures and each of the plurality of second sub-wavelength structures have a same shape.

11 . The optical filter of claim 10 , wherein the plurality of first sub-wavelength structures and the plurality of second sub-wavelength structures are arranged to face each other in a direction in which the first reflector and the second reflector are separated.

12 . The optical filter of claim 1 , wherein the plurality of first sub-wavelength structures and the plurality of second sub-wavelength structures are two-dimensionally arranged in regular triangular lattice forms, respectively.

13 . The optical filter of claim 1 , wherein the plurality of first sub-wavelength structures and the plurality of second sub-wavelength structures are two-dimensionally arranged in square lattice forms, respectively.

14 . The optical filter of claim 1 , wherein the plurality of first sub-wavelength structures or the plurality of second sub-wavelength structures are two-dimensionally arranged in a regular triangular lattice form, and the other of the plurality of first sub-wavelength structures and the plurality of second sub-wavelength structures are two-dimensionally arranged in a square lattice form.

15 . The optical filter of claim 1 , further comprising a third reflector provided separate from the second reflector,
wherein the third reflector comprises a plurality of third sub-wavelength structures that are two-dimensionally arranged and spaced apart by a third period based on a third rule.

16 . The optical filter of claim 15 , wherein each of the plurality of first sub-wavelength structures, each of the plurality of second sub-wavelength structures, and each of the plurality of third sub-wavelength structures have a same shape.

17 . The optical filter of claim 15 , wherein the plurality of first sub-wavelength structures, the plurality of second sub-wavelength structures, and the plurality of third sub-wavelength structures are arranged to face each other a direction in which the first reflector and the second reflector are separated.

18 . A spectrometer comprising:
a first optical filter comprising:
a first reflector comprising a plurality of first sub-wavelength structures that are two-dimensionally arranged and spaced apart by a first period based on a first rule, and
a second reflector comprising a plurality of second sub-wavelength structures that are two-dimensionally arranged and spaced apart by a second period based on a second rule;
a second optical filter comprising:
a third reflector comprising a plurality of third sub-wavelength structures that are two-dimensionally arranged and spaced apart by a third period based on a third rule, and
a fourth reflector comprising a plurality of fourth sub-wavelength structures that are two-dimensionally arranged and spaced apart by a fourth period based on a fourth rule; and
a sensor substrate comprising a plurality of light detectors that are arranged to face the first optical filter and the second optical filter, respectively.

19 . The spectrometer of claim 18 , wherein the sensor substrate, the first optical filter, and the second optical filter are formed monolithically.

20 . An electronic apparatus comprising:
a light source configured to emit light; a spectrometer provided on a path of light emitted from an object that is irradiated by the light emitted from the light source and configured to detect the light emitted from the object, the spectrometer comprising:
a first optical filter comprising:
a first reflector comprising a plurality of first sub-wavelength structures that are two-dimensionally provided and spaced apart by a first period based on a first rule, and
a second reflector comprising a plurality of second sub-wavelength structures that are two-dimensionally arranged and spaced apart by a second period based on a second rule;

a second optical filter comprising:
a third reflector comprising a plurality of third sub-wavelength structures that are two-dimensionally arranged and spaced apart by a third period based on a third rule, and
a fourth reflector comprising a plurality of fourth sub-wavelength structures that are two-dimensionally arranged and spaced apart by a fourth period based on a fourth rule; and

a sensor substrate comprising a plurality of light detectors provided to face the first optical filter and the second optical filter; and
a processor configured to determine at least one of a physical property, a shape, a position, and a motion of the object based on the light detected by the spectrometer.

21 . The optical filter of claim 1 ,
wherein the plurality of first sub-wavelength structures and the plurality of second sub-wavelength structures are arranged to face each other in a direction in which

Assignees

• Samsung Electronics Co Ltd

Inventors

• Baik Chanwook
• Cho Kyungsang

Classifications

• G01J2003/1213

  Filters in general, e.g. dichroic, band · CPC title

• G01J3/2803

  using photoelectric array detector · CPC title

• G01J3/0205 Primary

  Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows · CPC title

• G01J3/26

  using multiple reflection, e.g. Fabry-Perot interferometer, variable interference filters · CPC title

• G02B5/207

  comprising semiconducting materials · CPC title