Optical filter and optical device utilizing same

Patent metadata

Field	Value
Publication number	US-12558874-B2
Application number	US-202117194833-A
Country	US
Kind code	B2
Filing date	Mar 8, 2021
Priority date	Aug 22, 2016
Publication date	Feb 24, 2026
Grant date	Feb 24, 2026

Abstract

Provided is an optical filter including first and second reflection layers separated from each other, a dielectric region interposed between the first and second reflection layers and in which two materials of which refractive indexes are different are alternately disposed, and a buffer layer disposed between the dielectric region and at least one of the first and second reflection layers, wherein there are at least two filter regions in which relative volume ratios of the two materials alternately disposed are different.

First claim

The invention claimed is:

1 . An optical filter comprising:
a plurality of filter regions, wherein each of the plurality of filter regions comprises
a first reflection layer and a second reflection layer separated from each other;
a dielectric region interposed between the first reflection layer and the second reflection layer and in which two materials, of which refractive indexes are different, are alternately disposed; and
a buffer layer disposed between the dielectric region and at least one of the first reflection layer and the second reflection layer,
wherein the plurality of filter regions includes, at least, a first filter region and a second filter region adjacent to the first filter region, wherein the first filter region has a first structure and the second filter region has a second structure different from the first structure, wherein an overlap value of a pair of the plurality of filter regions is defined as Ip/Imax, wherein Ip defines a strength of a filter function at a point at which filter functions of the pair of the plurality of filter regions cross each other, and Imax denotes a maximum intensity of the filter function of the pair of the plurality of filter regions, wherein the first structure and the second structure are configured such that the overlap value of the first filter region and the second filter region is about 0.4 to about 1, and wherein a full width at half maximum (FWHM) of the filter function of each of the pair of filter regions is 100 nanometers or less.

2 . The optical filter of claim 1 , wherein a first relative volume ratio of the two materials alternately disposed in the first filter region is different from a second relative volume ratio of the two materials alternately disposed in the second filter region.

3 . The optical filter of claim 2 , wherein
a first relative width ratio of the two materials in the first filter region is different from a second relative width ratio of the two materials in the second filter region.

4 . The optical filter of claim 3 , wherein, in the two materials alternately disposed, a pair of two adjacent materials are allowed to respectively have same widths as a pair of two adjacent other materials in one direction.

5 . The optical filter of claim 2 , wherein the two materials are composed of a first material comprising in plurality and disposed at a pre-determined interval, and a second material surrounding the first material.

6 . The optical filter of claim 2 , wherein a width of a pair of the two materials is smaller than a wavelength of a light passing through the optical filter.

7 . The optical filter of claim 2 , wherein the filter regions, in which relative volume ratios of the two materials are different from each other, are in two or more directions in a plane.

8 . The optical filter of claim 2 , wherein the first reflection layer and the second reflection layer are a metal layer or a dispersion Bragg reflector (DBR).

9 . The optical filter of claim 2 , wherein the dielectric region comprises three or more materials.

10 . The optical filter of claim 2 , wherein the buffer layer is formed of a first or second material of the two materials.

11 . The optical filter of claim 2 , wherein an upper part of the second reflection layer comprises a wideband transmission filter and/or anti-reflection coating.

12 . The optical filter of claim 2 , wherein the filter regions respectively comprise different buffer layers.

13 . The optical filter of claim 2 , further comprising an intermediate reflection layer in a central region of the dielectric region, the intermediate reflection layer is parallel to the first reflection layer and the second reflection layer.

14 . The optical filter of claim 13 , further comprising second buffer layers interposed between the intermediate reflection layer and the first reflection layer and between the intermediate reflection layer and the second reflection layer, the second buffer layers have a same optical thickness as each other.

15 . An optical filter comprising:
a first optical filter region and a second optical filter region adjacent to each other, wherein each of the first optical filter region and the second optical filter region comprises
a first reflection layer and a second reflection layer separated from each other;
a dielectric region interposed between the first reflection layer and the second reflection layer and in which two materials, of which refractive indexes are different, are alternately disposed, one of the two materials having a first width and another of the two materials having a second width;
a first buffer layer disposed between the dielectric region and the first reflection layer; and
a second buffer layer disposed between the dielectric region and the second reflection layer,
wherein the first optical filter region comprises a first filter region and a second filter region in which a relative width ratio of the first width and the second width is different from a relative width ratio of the first width and the second width in the first filter region, wherein the second optical filter region comprises a first filter region and a second filter region in which a relative width ratio of the first width and the second width is different from a relative width ratio of the first width and the second width in the first filter region, wherein the second buffer layer of first optical filter region has a thickness greater than a thickness of the second buffer layer of second optical filter region, and wherein a relative volume ratio of the two materials alternately disposed in the first optical filter region and is different from a relative volume ratio of the two materials alternately disposed in the second optical filter region.

16 . The optical filter of claim 15 , wherein an overlap value of the first filter region and the second filter regions is about 0.4 to about 1, and
wherein the overlap value of the first filter region and the second filter region is defined as Ip/Imax, Ip defines a strength of a filter function at a point at which filter functions of the first filter region and the second filter region cross each other, and Imax denotes a maximum intensity of the filter function of the first filter region and the second filter region.

17 . The optical filter of claim 15 , wherein the first buffer layer of first filter region has a thickness same as a thickness of the first buffer layer of second filter region.

18 . An optical device comprising:
an optical detection region including an image sensor region and a spectrum sensor region; a color filter layer at the image sensor region on the optical detection region, the color filter layer is configured to filter an incident light to at least R, G, and B; and a spectral filter at the spectrum sensor region on the optical detection region, the spectral filter including a plurality of filter regions, wherein the color filter layer and the spectral filter are configured a unit pixel, wherein each of the plurality of filter regions comprises
a first reflection layer and a second reflection layer separated from each other;
a dielectric region interposed between the first reflection layer and the second reflection layer and in which two materials, of which refractive indexes are different, are alternately disposed; and
a buffer layer disposed between the dielectric region and at least one of the first reflection layer and the second reflection layer,
wherein the plurality of filter regions includes, at least, a

Assignees

• Samsung Electronics Co Ltd

Inventors

• Lee Kyeong Seok
• Hwang Gyu Weon
• Kim Won Mok
• Kim In Ho
• Lee Wook Seong
• Jeong Doo Seok

Classifications

• G02B5/28

  Interference filters · CPC title

• G02B5/201

  in the form of arrays · CPC title

• G02B1/11 Primary

  Anti-reflection coatings · CPC title

• B32B2307/418

  Refractive · CPC title

• B32B2307/416

  Reflective · CPC title