ALL-OPTICAL FREQUENCY UPCONVERTER AND ALL-OPTICAL FREQUENCY UPCONVERSION METHOD IN RADIO-OVER-FIBER SYSTEM

• US 20080298813A1
• Filed: 03/18/2008
• Published: 12/04/2008
• Est. Priority Date: 05/29/2007
• Status: Active Grant

• Current Assignee: Gwangju Institute of Science and Technology
• Original Assignee: Gwangju Institute of Science and Technology
• Inventors: Kim, Hyoung-Jun, SONG, Jong-In
• Granted Patent: US 8,027,589 B2
• Time in Patent Office: Days
• US Class Current: 398/178
• CPC Class Codes: H04B 10/25758 between a central unit and a single remote unit by means of an optical fibre

Abstract

Disclosed is an all-optical frequency upconverter in a radio-over-fiber system that outputs upconverted optical radio frequency (RF) signals using an optical intermediate frequency signal and an optical local oscillation signal. The all-optical frequency upconverter includes a semiconductor optical amplifier that mixes the optical intermediate frequency signal with the optical local oscillation signal through four wave mixing, and an optical filter that filters a plurality of frequency component signals, which are generated through the four wave mixing, to extract optical RF signals. According to the invention the system configuration can be made simple, and wide LO and IF frequency bandwidths can be provided.

Claims

1. An all-optical frequency upconversion method in a radio-over-fiber system, which uses a semiconductor optical amplifier and an optical filter, the all-optical frequency upconversion method comprising:

mixing an optical intermediate frequency signal with an optical local oscillation signal utilizing four wave mixing effect in a semiconductor optical amplifier; and

filtering optical radio frequency (RF) signals from number of frequency component signals generated through the four wave mixing in a semiconductor optical amplifier by using an optical filter.

2. The all-optical frequency upconversion method of claim 1, further comprising:

feeding the optical intermediate frequency signal and the optical local oscillation signal from a central station to the input of the semiconductor optical amplifier through the first optical fiber.

3. The all-optical frequency upconversion method of claim 2, further comprising:

transmitting the optical RF signals to a remote antenna station through the second optical fiber.

4. The all-optical frequency upconversion method of claim 3, further comprising:

opto-electrically converting the optical RF signals transmitted through the second optical fiber by using a photodetector in the remote antenna station to generate upconverted RF signals.

5. The all-optical frequency upconversion method of claim 4,

wherein the optical intermediate frequency signal has the electrical frequency of f_IF and the wavelength of ν

_IF, the optical local oscillation signal has the electrical frequency of f_LO and the wavelength of ν

_LO, and the RF signals have an electrical frequencies of f_LO+f_IF and f_LO−

f_IF.

6. The all-optical frequency upconversion method of claim 1,

wherein the optical intermediate frequency signal is a wavelength division multiplexing (WDM) signal.

7. An all-optical frequency upconversion method in an all-optical frequency upconverter of a radio-over-fiber system, the all-optical frequency upconversion method comprising:

mixing an optical intermediate frequency signal with an optical local oscillation signal through four wave mixing; and

filtering optical RF signals from number of frequency component signals generated through the four wave mixing.

8. The all-optical frequency upconversion method of claim 7,

wherein the mixing of the optical intermediate frequency signal with the optical local oscillation signal through the four wave mixing is performed in a semiconductor optical amplifier.

9. The all-optical frequency upconversion method of claim 7,

wherein the optical intermediate frequency signal is a WDM signal.

10. An all-optical frequency upconverter in a radio-over-fiber system that outputs upconverted optical RF signals through mixing an optical intermediate frequency signal and an optical local oscillation signal, the all-optical frequency upconverter comprising:

a semiconductor optical amplifier that mixes the optical intermediate frequency signal with the optical local oscillation signal through four wave mixing; and

an optical filter that filters optical RF signals from number of frequency component signals generated through the four wave mixing.

11. The all-optical frequency upconverter of claim 10,

wherein the semiconductor optical amplifier receives the optical intermediate frequency signal and the optical local oscillation signal from a central station through the first optical fiber.

12. The all-optical frequency upconverter of claim 11,

wherein the optical RF signals are transmitted to a remote antenna station through the second optical fiber.

13. The all-optical frequency upconverter of claim 10,

wherein the optical intermediate frequency signal is a WDM signal.