Method and device for measuring light radiation pressure

Patent metadata

Field	Value
Publication number	US-11650098-B2
Application number	US-202117147767-A
Country	US
Kind code	B2
Filing date	Jan 13, 2021
Priority date	Jan 16, 2020
Publication date	May 16, 2023
Grant date	May 16, 2023

Abstract

A device for measuring a light radiation pressure is provided which includes a torsion balance, a laser, a convex lens, and a line array detector. The laser is configured to emit a first laser beam. The convex lens is located on an optical path of the first laser beam and configured to focus the first laser beam to a surface of the reflector. The line array detector is configured to detect a reflected first laser beam reflected by the reflector. The disclosure also provides a method for measuring the light radiation pressure using the device.

First claim

What is claimed is:

1. A device for measuring a light radiation pressure, comprising:
a laser configured to emit a first laser beam;
a convex lens located on an optical path of the first laser beam and configured to focus the first laser beam to a surface of the reflector;
a torsion balance comprising a suspended carbon nanotube and a reflector hung on the carbon nanotube; wherein the reflector is configured to reflect a focused first laser beam; the reflector comprises a film, a first reflecting layer, and a second reflecting layer; and the film comprises at least two layers of two-dimensional materials stacked with each other, the film comprises a first surface and a second surface opposite to the first surface, and the first reflecting layer is located on the first surface and the second reflecting layer is located on the second surface; and
a line array detector configured to detect a reflected first laser beam reflected by the reflector.

2. The device of claim 1 , wherein the at least two layers of two-dimensional material is carbon nanotube film, graphene, boron nitride, molybdenum disulfide, tungsten disulfide or any combination thereof.

3. The device of claim 2 , wherein the carbon nanotube film comprises a plurality of first carbon nanotubes combined by van der Waals attractive force therebetween.

4. The device of claim 2 , wherein a number of layers of the two-dimensional material is less than 10.

5. The device of claim 1 , wherein the film is a carbon nanotube-graphene composite film comprising a first drawn carbon nanotube film, a second drawn carbon nanotube film, and a single layered graphene film sandwiched between the first drawn carbon nanotube film and the second drawn carbon nanotube film.

6. The device of claim 5 , wherein the first drawn carbon nanotube film comprises a plurality of first carbon nanotubes, and the second drawn carbon nanotube film comprises a plurality of second carbon nanotubes, an angle between an extending direction of the first carbon nanotubes and an extending direction of the second carbon nanotubes is about 90 degrees.

7. The device of claim 5 , wherein carbon atoms of the single layered graphene film is sp 3 hybridized to carbon atoms of the first drawn carbon nanotube film.

8. The device of claim 1 , wherein a material of the first reflecting layer is aluminum, silver, copper, chromium, platinum, or any combination thereof.

9. The device of claim 1 , wherein a thickness of the first reflecting layer is in a range from about 5 nm to about 20 nm.

10. The device of claim 1 , wherein the film is an axisymmetric shaped film, and the carbon nanotube is located on a symmetry axis of the film.

11. The device of claim 1 , wherein the carbon nanotube is prepared by removing an outer wall of a multi-walled carbon nanotube.

12. The device of claim 1 , further comprising a substrate configured to fix and support the carbon nanotube, wherein a space is formed on a surface of the substrate, and the carbon nanotube is arranged across the space.

13. The device of claim 12 , wherein the carbon nanotube comprises a first end, a second end opposite to the first end, and a middle portion located between the first end and the second end; the first end and the second end are fixed on a surface of the substrate, the middle portion is suspended on the space.

14. The device of claim 12 , wherein the space is a through hole or a blind hole.

15. The device of claim 1 , further comprising an optical microscope configured to observe the torsion balance.

16. A method for measuring a light radiation pressure using the device of claim 1 , comprising:
S1, emitting a first laser beam using the laser, wherein a light radiation pressure of the first laser beam is known and defined as F 1 , the first laser beam is focused by the convex lens and then irradiates to a surface of the reflector, the reflector is deflected under the first laser beam, and the first laser beam is reflected at the reflector to form a first reflected beam, the first reflected beam is received by the line array detector at a first position x 1 ;
S2, emitting a second laser beam using the laser, wherein a light radiation pressure of the second laser beam is unknown and defined as F 2 , the second laser beam is focused by the convex lens and then irradiates to the surface of the reflector, the reflector is deflected under the second laser beam, and the second laser beam is reflected at the reflector to form a second reflected beam, the second reflected beam is received by the line array detector at a second position x 2 ;
S3, calculating a deflection angle Δθ between the second reflected beam and the first reflected beam according to the first position x 1 and the second position x 2 :

Δ
⁢
θ

=

x
2

-

x
1

D

,

wherein D is a distance from the reflector to the line array detector; and
S4, calculating F 2 according to a torsion Hooke's law: ×Δα=ΔF×L, wherein κ is a torsional stiffness of the carbon nanotube;

Δα
=

Δ
⁢
θ

2

;

ΔF=F 2 −F 1 ; L is a length of an arm.

17. The method of claim 16 , wherein the line array detector is configured to acquire a plurality of data at intervals of 1 millisecond, and then calculate an average value as the first position x 1 .

Assignees

• Univ Tsinghua
• Hon Hai Prec Ind Co Ltd

Inventors

• Cong Lin
• Yuan Zi
• Jiang Kai-Li
• Fan Shou-Shan

Classifications

• C01P2004/24

  Nanoplates, i.e. plate-like particles with a thickness from 1-100 nanometer · CPC title

• G01J1/0414

  using plane or convex mirrors, parallel phase plates, or plane beam-splitters · CPC title

• C01B21/064

  with boron · CPC title

• G01J1/56 Primary

  using radiation pressure or radiometer effect · CPC title

• C01P2004/02

  obtained by optical microscopy · CPC title