Wavelength division multiplexing passive optical network for providing both of broadcasting service and communication service and central office used thereof

• US 8,290,370 B2
• Filed: 09/19/2006
• Issued: 10/16/2012
• Est. Priority Date: 09/20/2005
• Status: Expired due to Fees

• Current Assignee: Korea Advanced Institute of Science and Technology
• Original Assignee: Korea Advanced Institute of Science and Technology
• Inventors: Lee, Chang-Hee, Moon, Jung-Hyung, Choi, Ki-Man
• Primary Examiner(s): Park, Kinam
• Application Number:
  US11/992,243
• Publication Number:
  US 20090185807A1
• Time in Patent Office: 2,219 Days
• Field of Search: 398/72, 398/71, 398/69, 398/68
• US Class Current: 398/72
• CPC Class Codes: H04B 10/506 Multiwavelength transmitters
• CPC Class Codes: H04B 10/572 Wavelength control
• CPC Class Codes: H04J 14/0226 Fixed carrier allocation, e.g. according to service
• CPC Class Codes: H04J 14/0232 for downstream transmission
• CPC Class Codes: H04J 14/0246 using one wavelength per ONU
• CPC Class Codes: H04J 14/025 using one wavelength per ONU, e.g. for transmissions from-ONU-to-OLT or from-ONU-to-ONU
• CPC Class Codes: H04J 14/0282 WDM tree architectures

Abstract

Disclosed is a wavelength division multiplexing passive optical network for simultaneously providing a broadcasting service and a data service by employing a broadband light source, which uses mutually injected Fabry-Perot laser diodes, as well as a central office used for the same.

Claims

1. A central office used in a wavelength division multiplexing passive optical network, which provides a broadcasting service and a communication service simultaneously, the central office comprising:

a plurality of downstream optical transmitters for outputting first optical signals for providing a plurality of subscribers with a data service;

a plurality of upstream optical receivers for receiving optical signals of upstream data from the subscribers and converting the optical signals into electrical signals;

a wavelength division multiplexer/demultiplexer for multiplexing/demultiplexing the optical signals;

a broadband light source for broadcasting signals comprising mutually injected Fabry-Perot laser diodes which are coupled to the wavelength division multiplexer/demultiplexer to output optical signals for providing the subscribers with a broadcasting service; and

a modulator coupled to the mutually injected Fabry-Perot laser diodes for modulating the optical signals of the mutually injected Fabry-Perot laser diodes into broadcasting signals.

2. The central office as claimed in claim 1 wherein the Fabry-Perot laser diodes used by the broadband light source have anti-reflective coating.

3. The central office as claimed in claim 1, further comprising light sources for the downstream optical transmitters, the light sources for the downstream optical transmitters being a wavelength-locked Fabry-Perot laser diode or a semiconductor optical amplifier, a broadband light source having been injected into the semiconductor optical amplifier from outside.

4. The central office as claimed in claim 1, further comprising light sources for the downstream optical transmitters, the light sources for the downstream optical transmitters being a distributed feedback laser diode.

5. The central office as claimed in claim 1, wherein the wavelength division multiplexer/demultiplexer is an arrayed waveguide grating or thin film filters.

6. The central office as claimed in claim 1, wherein the modulator for optically modulating the broadband light source into broadcasting signals is an external modulator or a modulator adopting a direct modulation method.