Image sensing device including optical elements and method for manufacturing the same
Image sensing devices including meta lenses and methods for manufacturing the image sensing devices are disclosed. In an embodiments, an image sensing device includes a plurality of microlenses including first to fourth microlenses arranged in a (2×2) matrix structure, a plurality of optical filters disposed under the first to fourth microlens, and configured to correspond to the first to fourth microlenses, one microlens per optical filter, respectively, and an optical element disposed at a center of the (2×2) matrix structure among the first to fourth microlenses and configured to separate incident light into light rays of in different wavelength ranges of different colors to guide each of the light rays to one of the plurality of optical filters of a corresponding color.
1 . An image sensing device comprising:
a plurality of microlenses including first to fourth microlenses arranged in a (2×2) matrix structure;
a plurality of optical filters disposed under the first to fourth microlenses, and configured to correspond to the first to fourth microlenses, one microlens per optical filter, respectively; and
an optical element disposed at a center of the (2×2) matrix structure among the first to fourth microlenses and configured to separate incident light into light rays of in different wavelength ranges of different colors to guide each of the light rays to one of the plurality of optical filters of a corresponding color.
2 . The image sensing device according to claim 1 , wherein the plurality of optical filters includes first to fourth optical filters,
wherein the first optical filter is configured to transmit light of a first color, the second optical filter is configured to transmit light of a second color, the third optical filter is configured to transmit light of a third color, and the fourth optical filter is configured to transmit light of the first color.
3 . The image sensing device according to claim 2 , wherein:
the first color is green, the second color is red, and the third color is blue.
4 . The image sensing device according to claim 1 , wherein the optical element includes:
a thin film layer includes a first surface upon which the incident light is incident and a second surface facing or opposite to the first surface,
wherein the second surface is in contact with a plurality of nanoparticles arranged in a predetermined pattern.
5 . The image sensing device according to claim 4 , wherein:
the predetermined pattern is repeatedly disposed on the second surface at a certain interval.
6 . The image sensing device according to claim 4 , wherein:
the plurality of nanoparticles includes at least one of gallium nitride, silicon nitride, or titanium dioxide.
7 . The image sensing device according to claim 4 , wherein:
each of the plurality of nanoparticles is formed in a cylindrical shape.
8 . The image sensing device according to claim 7 , wherein:
the plurality of nanoparticles includes a first nano-cylinder and a second nano-cylinder that have different diameters.
9 . The image sensing device according to claim 4 , wherein:
the plurality of nanoparticles is formed in a shape corresponding to one of a triangular pillar, a square pillar, a hexagonal pillar, or an octagonal pillar.
10 . The image sensing device according to claim 4 , wherein:
the thin film layer includes silicon dioxide or polymethyl methacrylate (PMMA).
11 . The image sensing device according to claim 4 , wherein:
the plurality of optical filters includes a first optical filter configured to transmit red light and a second optical filter configured to transmit blue light; and
the predetermined pattern includes a first region in which the optical element overlaps the first optical filter and a second region in which the optical element overlaps the second optical filter, wherein the first region includes more nanomaterials than second region.
12 . The image sensing device according to claim 4 , wherein:
the plurality of nanoparticles is arranged to have a height of 700 nm or less in a direction perpendicular to the second surface.
13 . The image sensing device according to claim 1 , wherein:
the optical element is in contact with each of the first to fourth microlenses.
14 . A method for manufacturing an image sensing device comprising:
arranging first to fourth microlenses in a (2×2) matrix structure;
arranging an optical element at a center of the (2×2) matrix structure; and
forming first to fourth optical filters respectively corresponding to the first to fourth microlenses,
wherein the optical element is configured to separate incident light into light rays corresponding to different colors and guides each of the light rays to one of the first to fourth optical filters of a corresponding color.
15 . The method according to claim 14 , further comprising:
determining a structure of the optical element using a program configured to perform an optical simulation.
16 . The method according to claim 15 , wherein:
the optical simulation is performed using one of a finite difference time domain method, a finite element method, or a moment method.
17 . The method according to claim 15 , further comprising:
determining whether the structure of the optical element separates the incident light into the light rays corresponding to different colors and guides each of the light rays to one of the first to fourth optical filters of a corresponding color.
18 . The method according to claim 14 , further comprising:
determining a structure of the optical element using a program including a deep learning technology.
19 . The method according to claim 18 , wherein:
the deep learning technology is implemented using one of a freeform design method, a genetic algorithm method, a particle swarm optimization method, or an adjacent method.
20 . The method according to claim 18 , further comprising:
determining whether the structure of the optical element separates the incident light into the light rays corresponding to different colors and guides each of the light rays to one of the first to fourth optical filters of a corresponding color.
21 . The method according to claim 14 , wherein:
the first optical filter is configured to transmit light of a first color;
the second optical filter is configured to transmit light of a second color;
the third optical filter is configured to transmit light of a third color; and
the fourth optical filter is configured to transmit light of the first color.
22 . The method according to claim 21 , wherein the optical element is configured to:
guide the first-color light included in the incident light to the first optical filter or the fourth optical filter;
guide the second-color light included in the incident light to the second optical filter; and
guide the third-color light included in the incident light to the third optical filter.