Apparatus and method for generating optical carrier for microwave and millimeterwave photonics system

• US 20050141582A1
• Filed: 06/28/2004
• Published: 06/30/2005
• Est. Priority Date: 12/26/2003
• Status: Active Grant

• Current Assignee: Intellectual Discovery Co., Ltd.
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Cho, Hyunwoo, Lim, Sang-Kyu, Ko, Je-Soo, Park, Heuk, Lee, Sang-Soo
• Granted Patent: US 7,142,570 B2
• Time in Patent Office: Days
• US Class Current: 372/84
• CPC Class Codes: G02F 2/002 using optical mixing
• CPC Class Codes: H01S 3/067 Fibre lasers
• CPC Class Codes: H01S 3/302 in an optical fibre
• CPC Class Codes: H03D 9/00 Demodulation or transference of modulation of modulated electromagnetic waves demodulating light, transferring modulation in light waves G02F2/00
• CPC Class Codes: H04B 10/50 Transmitters

Abstract

An apparatus and a method for generating an optical carrier is disclosed. The apparatus includes: a light source generating a pump light; a SBS generator for stimulated Brillouin scattering the pump light to generate a stokes light from the light source; an attenuator for controlling an amplitude of the pump light from the light source to generate an amplitude controlled pump light; and a detector for heterodyne beating the stokes light and the amplitude controlled pump light to generate an optical carrier.

Claims

1. An apparatus for generating an optical carrier for a microwave photonics system, the apparatus comprising:

a light source generating a pump light;

means for stimulated Brillouin scattering the pump light to generate a stokes light from the light source;

an attenuator for controlling an amplitude of the pump light from the light source to generate an amplitude controlled pump light; and

means for heterodyne beating the stokes light and the amplitude controlled pump light to generate an optical carrier.

2. The apparatus of the claim 1, further comprising:

means for passing the pump light from the light source to the stimulated Brillouin scattering means and passing the stokes light and the amplitude controlled pump light to the heterodyne beating means; and

means for reflecting the amplitude controlled pump light from the stimulated Brillouin scattering means to the passing means.

3. The apparatus of the claim 1, wherein the pump light has an optical power density higher than a predetermined SBS threshold value.

4. The apparatus of claim 3, wherein the predetermined threshold value is approximately 10 dBm to approximately 13 dBm.

5. The apparatus of claim 1, wherein the stimulated Brillouin scattering means minutely controls a frequency of the stokes light according to external environment factor such as a temperature.

6. The apparatus of claim 1, wherein the stimulated Brillouin scattering means is an optical fiber.

7. The apparatus of claim 1, wherein the stimulated Brillouin scattering means includes a frequency generator such as a Brillouin/erbium fiber laser (BEFL) and a filter.

15. The apparatus of claim 1, wherein the stimulated Brillouin scattering means includes a frequency generator such as a Brillouin/erbium fiber laser (BEFL) and a filter.

8. An apparatus for generating an optical carrier for a microwave photonics system, the apparatus comprising:

a light source generating a pump light;

means for splitting the pump light into a first pump light and a second pump light;

means for stimulated Brilouin scattering the first pump light to generate a stokes light from the splitting means;

an attenuator for controlling an amplitude of the first pump light from the diverging means to generate an amplitude controlled second pump light; and

means for heterodyne beating the stokes light and the amplitude controlled second pump light to generate an optical carrier.

9. The apparatus of the claim 8, further comprising:

a terminator for terminating the first pump light from the stimulated Brillouin scattering means; and

means for reflecting the amplitude controlled second pump light from the stimulated Brillouin scattering means to the heterodyne beating means.

10. The apparatus of the claim 8, wherein the diverging means receives the stokes light from the stimulated Brillouin scattering means and the amplitude controlled second pump light from the attenuator and passes the stokes light and the amplitude controlled second pump light to the heterodyne beating means.

11. The apparatus of the claim 8, wherein the pump light has an optical power density higher than a predetermined threshold value.

12. The apparatus of claim 11, wherein the predetermined threshold value is approximately 10 dBm to approximately 13 dBm.

13. The apparatus of claim 8, wherein the stimulated Brillouin scattering means minutely controls a frequency of the stokes light according to external environment factor such as a temperature.

14. The apparatus of claim 8, wherein the stimulated Brillouin scattering means is an optical fiber.

16. A method for generating an optical carrier for a microwave photonics system, the method comprising the steps of:

a) generating a pump light having an optical density higher than a predetermined threshold value at a light source;

b) stimulated Brillouin scattering the pump light for generating a stokes light at a stimulated brillouin scattering generator;

c) controlling an amplitude of the pump light wave passed through the stimulated Brillouin scattering generator to generate an amplitude controlled pump light at an optical attenuator;

d) changing a propagation direction of the amplitude controlled pump light wave to the stimulated Brillouin scattering generator;

e) passing the stokes light and the amplitude controlled pump light at an optical circulator; and

f) generating an optical carrier by heterodyne beating the stokes light and the amplitude controlled pump light.

17. A method for generating an optical carrier for a microwave photonics system, the method comprising the steps of:

a) generating a pump light having an optical density higher than a predetermined threshold value;

b) splitting the pump light into a first pump light and a second pump light;

c) generating a stokes light by using the first pump light;

d) controlling an amplitude of the second pump light;

e) combining the stokes light and the amplitude controlled second pump light; and

f) detecting an optical carrier from the combined light by heterodyne beating the combined light.