Optical component and image sensor comprising an optical component

Patent metadata

Field	Value
Publication number	US-12575203-B2
Application number	US-202118017257-A
Country	US
Kind code	B2
Filing date	Jul 22, 2021
Priority date	Jul 30, 2020
Publication date	Mar 10, 2026
Grant date	Mar 10, 2026

Abstract

In example embodiments, an optical component includes a dielectric structure having a substantially rectangular cross-section with an upper surface and a lower surface. A first electrically conducting layer is provided on the upper surface, where the first electrically conducting layer has a first opening positioned to accept incoming electromagnetic radiation. The second electrically conducting layer has a second opening positioned to emit electromagnetic radiation, e.g. toward a CMOS sensor pixel in a silicon substrate. The dimensions of the optical component are configured to provide constructive interference for incident radiation of a selected wavelength.

First claim

What is claimed:

1 . An optical component comprising:
a substantially rectangular dielectric element having an upper surface, a lower surface, and at least one side surface, the dielectric element being arranged on a silicon substrate; a first electrically conductive layer disposed on the upper surface of the dielectric element, the first electrically conducting layer having a first opening of a first width configured to accept incident electromagnetic radiation; and a second electrically conductive layer disposed between the lower surface of the dielectric element and a top surface of the silicon substrate, the second electrically conductive layer having a second opening of a second width configured for emission of the incident electromagnetic radiation of a selected wavelength determined by the first width and the second width into the silicon substrate, wherein the incident electromagnetic radiation undergoes diffraction at the at least one side surface of the dielectric element and at the first opening in the first electrically conductive layer and at the second opening in the second electrically conductive layer, such that diffracted electromagnetic radiation waves interfere constructively with spherical electromagnetic radiation waves generated at the first opening, taking into account reflections from the first electrically conductive layer, the second electrically conductive layer, and the at least one side surface of the dielectric element, thereby creating a focused optical hotspot in the silicon substrate.

2 . The optical component of claim 1 , wherein the first width and the second width are substantially the same.

3 . The optical component of claim 1 , wherein the first opening and the second opening are substantially centered on the dielectric element.

4 . The optical component of claim 1 , wherein the silicon substrate comprises es a photodetector.

5 . The optical component of claim 1 , wherein the dielectric element has a height h element between 1600 nm and 1900 nm and a width d element between 1100 nm and 1400 nm.

6 . The optical component of claim 1 , wherein the dielectric element has a height h element between 900 nm and 1300 nm and a width d element between 750 nm and 1050 nm.

7 . The optical component of claim 1 , wherein the first opening and the second opening have a width between 150 nm and 200 nm.

8 . The optical component of claim 1 , configured to selectively transmit incoming electromagnetic radiation with wavelength λ inc , wherein a height h element of the dielectric element is substantially equal to λ inc /(n H −n L ), where n H is a refractive index of the dielectric element and n L is a refractive index of an ambient medium.

9 . The optical component of claim 1 , configured to selectively transmit incoming electromagnetic radiation with wavelength λ inc , wherein a width d element of the dielectric element is no less than

2
⁢

λ

i
⁢
n
⁢
c

⁢

tan
⁡
(

θ
B

)

n
H

-

n
L

,

where

θ
B

=

90
⁢
°

-

sin

-
1

(

n
L

/

n
H

)

2

,

 and where n H is a refractive index of the dielectric element and n L is a refractive index of an ambient medium.

10 . A method comprising:
directing electromagnetic radiation on an optical component, wherein the optical component comprises:
a substantially rectangular dielectric element having an upper surface, a lower surface, and at least one side surface, the dielectric element being arranged on a silicon substrate;
a first electrically conductive layer disposed on the upper surface of the dielectric element, the first electrically conducting layer having a first opening of a first width configured to accept incident electromagnetic radiation; and
a second electrically conductive layer disposed between the lower surface of the dielectric element and a top surface of the silicon substrate, the second electrically conductive layer having a second opening of a second width configured for emission of the incident electromagnetic radiation of a selected wavelength determined by the first width and by the second width into the silicon substrate,
wherein the incident electromagnetic radiation undergoes diffraction at the at least one side surface of the dielectric element and at the first opening in the first electrically conductive layer and at the second opening in the second electrically conductive layer, such that diffracted electromagnetic radiation waves interfere constructively with spherical electromagnetic radiation waves generated at the first opening, taking into account reflections from the first electrically conductive layer, the second electrically conductive layer, and the at least one side surface of the dielectric element, thereby creating a focused optical hotspot in the silicon substrate.

11 . The method of claim 10 , wherein a height h element of the dielectric element is substantially equal to λ inc /(n H −n L ), where n H is a refractive index of the dielectric element and n L is a refractive index of an ambient medium.

12 . The method of claim 10 , wherein a width d element of the dielectric element is no less than

2
⁢

λ
inc

⁢

tan
⁡
(

θ
B

)

n
H

-

n

Assignees

• Interdigital Ce Patent Holdings Sas

Inventors

• Varghese Bobin
• Shramkova Oksana
• Blonde Laurent
• Drazic Valter

Classifications

• H10F39/811

  Interconnections · CPC title

• H10F39/18

  Complementary metal-oxide-semiconductor [CMOS] image sensors; Photodiode array image sensors · CPC title

• H10F39/806

  Optical elements or arrangements associated with the image sensors · CPC title

• G02B5/008

  Surface plasmon devices (diffractive gratings with a pitch less than or comparable to the wavelength G02B5/1809; surface plasmons in integrated optics G02B6/1226; optical analysis of materials by means of surface plasmons G01N21/553) · CPC title

• G02B5/288

  comprising at least one thin film resonant cavity, e.g. in bandpass filters · CPC title