IP Library › Granted Patent US 12674703
Granted Patent B2
US 12674703 · App. 18/889,320 · Granted Jul 7, 2026

Using a strong optical beam to detect a weak optical beam

Inventor: Chian Chiu Li (Fremont, CA)
G01J1/4257G01J1/0411G01J1/0425G01J2001/442
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Quick Facts
Patent No.
US 12674703
App. No.
18/889,320
Granted
Jul 7, 2026
Kind
B2
Abstract

Methods and apparatus for detecting weak beams and single photons. A reference beam interferes with a weak beam to generate an output beam. Characteristics such as propagation direction of the output beam are used to detect the weak beam. The methods further include using an array of reference beams to detect an image formed by weak beams.

Claims (38)

1 . A method for detecting an image formed by a plurality of first optical beams of a first wavelength, comprising:

providing a plurality of second optical beams of a second wavelength, a width of one of the plurality of second optical beams being smaller than one and a half times of the second wavelength;

causing one of the plurality of first optical beams and the one of the plurality of second optical beams to interfere to generate an output beam;

detecting a characteristic of the output beam; and

using the characteristic to detect a pixel of the image.

2 . The method according to claim 1 , further comprising:

providing a substrate including a plurality of holes, each first optical beam passing through a corresponding one of the plurality of holes.

3 . The method according to claim 1 wherein a width of the one of the plurality of first optical beams is smaller than one and a half times of the first wavelength.

4 . The method according to claim 1 wherein a spacing between the one of the plurality of first optical beams and the one of the plurality of second optical beams is smaller than one and a half times of the second wavelength.

5 . The method according to claim 1 wherein power of the one of the plurality of second optical beams is at least five times larger than power of the one of the plurality of first optical beams.

6 . The method according to claim 1 wherein the one of the plurality of first optical beams and the one of the plurality of second optical beams are coherent.

7 . The method according to claim 1 , further comprising:

adjusting a phase of the one of the plurality of second optical beams to change the characteristic of the output beam.

8 . A method for detecting an image formed by a plurality of first optical beams of a first wavelength, comprising:

providing a plurality of second optical beams of a second wavelength, power of one of the plurality of second optical beams beam being at least five times larger than power of one of the plurality of first optical beams;

causing the one of the plurality of first optical beams and the one of the plurality of second optical beams to interfere to generate an output beam;

detecting a characteristic of the output beam; and

using the characteristic to detect a pixel of the image.

9 . The method according to claim 8 , further comprising:

providing a substrate including a plurality of holes, each first optical beam passing through a corresponding one of the plurality of holes.

10 . The method according to claim 8 wherein a width of the one of the plurality of first optical beams is smaller than one and a half times of the first wavelength.

11 . The method according to claim 8 wherein a width of the one of the plurality of second optical beams is smaller than one and a half times of the second wavelength.

12 . The method according to claim 8 wherein a spacing between the one of the plurality of first optical beams and the one of the plurality of second optical beams is smaller than one and a half times of the second wavelength.

13 . The method according to claim 8 wherein the one of the plurality of first optical beams and the one of the plurality of second optical beams are coherent.

14 . The method according to claim 8 , further comprising:

adjusting a phase of the one of the plurality of second optical beams to change the characteristic of the output beam.

15 . A method for detecting an image formed by a plurality of first optical beams of a first wavelength, comprising:

providing a plurality of second optical beams of a second wavelength, a spacing between one of the plurality of first optical beams and one of the plurality of second optical beams being smaller than one and a half times of the second wavelength;

causing the one of the plurality of first optical beams and the one of the plurality of second optical beams to interfere to generate an output beam;

detecting a characteristic of the output beam; and

using the characteristic to detect a pixel of the image.

16 . The method according to claim 15 , further comprising:

providing a substrate including a plurality of holes, each first optical beam passing through a corresponding one of the plurality of holes.

17 . The method according to claim 15 wherein a width of the one of the plurality of first optical beams is smaller than one and a half times of the first wavelength.

18 . The method according to claim 15 wherein a width of the one of the plurality of second optical beams is smaller than one and a half times of the second wavelength.

19 . The method according to claim 15 wherein power of the one of the plurality of second optical beams is at least five times larger than power of the one of the plurality of first optical beams.

20 . The method according to claim 15 , further comprising:

adjusting a phase of the one of the plurality of second optical beams to change the characteristic of the output beam.