Single-photon Raman optical frequency comb source

Patent metadata

Field	Value
Publication number	US-12224548-B2
Application number	US-202318716704-A
Country	US
Kind code	B2
Filing date	Apr 21, 2023
Priority date	Apr 21, 2023
Publication date	Feb 11, 2025
Grant date	Feb 11, 2025

Abstract

A single-photon Raman optical frequency comb source is provided, including: a light source assembly, a filtering mechanism, at least three electro-optical modulators, a wavelength division multiplexer and a single photon generating mechanism. The light source assembly is configured to generate a Raman scattering light. The filtering mechanism is configured to pass a light having a specific wavelength, to filter the Raman scattering light and obtain at least three Raman scattering spectral lines. Each electro-optical modulator is configured to modulate a frequency of one of the Raman scattering spectrum lines in one-to-one correspondence, so as to cause a frequency shift of the Raman scattering spectrum line. The wavelength division multiplexer is configured to multiplex all modulated Raman scattering spectral lines and output a Raman optical frequency comb. The single photon generating mechanism is configured to adjust the Raman optical frequency comb to obtain a single-photon Raman optical frequency comb.

First claim

What is claimed is:

1. A single-photon Raman optical frequency comb source, comprising:
a light source assembly configured to generate a Raman scattering light;
a filtering mechanism configured to pass a light having a specific wavelength, so as to filter the Raman scattering light and obtain at least three Raman scattering spectral lines;
at least three electro-optical modulators, wherein each electro-optical modulator is configured to modulate a frequency of one Raman scattering spectrum line of the at least three Raman scattering spectrum lines in one-to-one correspondence, so as to cause a frequency shift of the Raman scattering spectrum line;
a wavelength division multiplexer configured to multiplex all modulated Raman scattering spectral lines and output a Raman optical frequency comb; and
a single photon generating mechanism configured to adjust the Raman optical frequency comb to obtain a single-photon Raman optical frequency comb.

2. The single-photon Raman optical frequency comb source according to claim 1 , wherein the light source assembly comprises:
a laser configured to emit a laser beam; and
a gas cavity filled with gas, wherein the laser beam is incident on gas molecules of the gas and Raman scattering occurs, so as to obtain an initial Raman scattering light;
wherein the filtering mechanism is configured to receive a transverse Raman scattering light of the initial Raman scattering light output from the gas cavity, and a transmission direction of the transverse Raman scattering light is perpendicular to a transmission direction of the laser beam.

3. The single-photon Raman optical frequency comb source according to claim 2 , wherein determining the light having the specific wavelength comprises:
determining the light having the specific wavelength according to a differential scattering cross section of the gas and an anti-Stokes Raman frequency shift of the gas.

4. The single-photon Raman optical frequency comb source according to claim 3 , wherein the differential scattering cross section of the gas is expressed by:

(

d
⁢
σ

d
⁢
Ω

)

J

R
⁢
R

,
VRR

=

112
⁢

π
4

15

⁢

g
⁡
(
J
)

⁢
hc
⁢

B
0

(

ν
0

+

Δν
⁡
(
J
)

)

4

⁢

γ
2

(

2
⁢
I

+
1

)

2

⁢

k
B

⁢
T

⁢

X
⁡
(
J
)

⁢

exp
[

-

E

r
⁢
o
⁢
t

(
J
)

k
B

⁢
T

]

where J represents a rotational quantum number of the gas molecules, J=2, 3, 4 . . . ,

(

d
⁢
σ

d
⁢
Ω

)

J

R
⁢
R

,
VRR

 represents a differential scattering cross section of the gas, g(J) represents a nuclear spin statistical weight of the gas molecules, h represents a Planck constant, c represents a speed of light in vacuum, v 0 represents a wave number of the laser, γ represents an anisotropy parameter of polarization intensity of the gas molecules, I represents a nuclear spin quantum number of the gas molecules, k B represents a Boltzmann constant, T represents a temperature, X(J) represents a rotational transition square matrix, E rot (J) represents a rotational energy of the gas molecules, Δv(J) represents an anti-Stokes frequency shift of the gas, and B 0 represents a rotation constant of the gas molecules,
the anti-Stokes Raman frequency shift of the gas is expressed by:
Δ v ( J )=2 B 0 (2 J− 1)− D 0 [3(2 J− 1)+(2 J− 1) 3 ];

where D 0 represents a centrifugal distortion constant of the gas molecules.

5. The single-photon Raman optical frequency comb source according to claim 2 , wherein the gas is nitrogen;
the electro-optical modulator is further configured to modulate an intensity of the Raman scattering line in one-to-one correspondence.

6. The single-photon Raman optica

Assignees

• Univ Science & Technology China

Inventors

• Wang Chong
• Yang Haocheng
• Xue Xianghui
• Li Yudie
• Chen Tingdi

Classifications

• H01S3/305

  in a gas · CPC title

• H01S3/115

  using intracavity electro-optic devices · CPC title

• H01S3/0085 Primary

  Modulating the output, i.e. the laser beam is modulated outside the laser cavity · CPC title

• H01S3/0078

  Frequency filtering · CPC title

• H01S3/302

  in an optical fibre · CPC title