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

Patent metadata

Field	Value
Publication number	US-10976477-B2
Application number	US-201916437832-A
Country	US
Kind code	B2
Filing date	Jun 11, 2019
Priority date	Aug 31, 2018
Publication date	Apr 13, 2021
Grant date	Apr 13, 2021

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 in a horizontal direction and spaced apart by a first period based on a first rule;
a second reflector provided separate from the first reflector in a vertical direction, the second reflector comprising a plurality of second sub-wavelength structures that are two-dimensionally arranged in the horizontal direction and spaced apart by a second period based on a second rule, the plurality of second sub-wavelength structures corresponding to the plurality of first sub-wavelength structures in the vertical direction,
wherein when viewed from a plan view, shapes of the plurality of first sub-wavelength structures and shapes of the plurality of second sub-wavelength structures are without shape anisotropy, and
wherein a width of each of the plurality of first sub-wavelength structures is greater than a width of each of the corresponding plurality of second sub-wavelength structures.

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 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 an upper surface of the substrate.

4. The optical filter of claim 3 , 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.

5. The optical filter of claim 4 , 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.

6. The optical filter of claim 5 , wherein the first material layer and the second material layer comprise a same material.

7. 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.

8. 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.

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 ,
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.

16. An optical filter comprising:
a first reflector comprising a plurality of first sub-wavelength structures that are two-dimensionally arranged in a horizontal direction and spaced apart by a first period based on a first rule;
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 in the horizontal direction and spaced apart by a second period based on a second rule; and
a third reflector provided separate from the second reflector and opposite to the first reflector with respect to the second reflector in a vertical direction, the third reflector comprising a plurality of third sub-wavelength structures that are two-dimensionally arranged in the horizontal direction and spaced apart by a third period based on a third rule.

17. The optical filter of claim 16 , 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.

18. The optical filter of claim 16 , 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, the second reflector, and the third reflector are separated.

19. A spectrometer comprising:
a first optical filter comprising:
a first reflector comprising a plurality of first sub-wavelength structures that are two-dimensionally arranged in a horizontal direction 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 in the horizontal direction and spaced apart by a second period based on a second rule, the second reflector being provided separate from the first reflector in a vertical direction and the plurality of second sub-wavelength structures corresponding to the plurality of first sub-wavelength structures in the vertical direction,
wherein when viewed from a plan view, shapes of the plurality of first sub-wavelength structures and shapes of the plurality of second sub-wavelength structures are without shape anisotropy, and
wherein a width of each of the plurality of first sub-wavelength structures is greater than a width of each of the corresponding plurality of second sub-wavelength structures;

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

Assignees

• Samsung Electronics Co Ltd

Inventors

• Baik Chanwook
• Cho Kyungsang

Classifications

• G02B5/207

  comprising semiconducting materials · CPC title

• G01J3/26

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

• G01J3/2803

  using photoelectric array detector · CPC title

• G01J3/28

  Investigating the spectrum (using colour filters G01J3/51) · CPC title

• G01J3/18

  using diffraction elements, e.g. grating (gratings per se G02B) · CPC title