Reflective semiconductor optical amplifier (RSOA), RSOA module having the same, and passive optical network using the same

• US 7,738,167 B2
• Filed: 12/04/2006
• Issued: 06/15/2010
• Est. Priority Date: 12/09/2005
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Lee, Woo-Ram, Kim, Byoung Whi, Kim, Tae Yeon, Park, Mahn Yong
• Primary Examiner(s): Hellner; Mark
• Application Number:
  US11/633,349
• Publication Number:
  US 20070133990A1
• Time in Patent Office: 1,289 Days
• Field of Search: 398/72, 398/99, 359/344
• US Class Current: 359/344
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G02B 6/12004 Combinations of two or more optical elements
• CPC Class Codes: G02B 6/4202 for coupling an active element with fibres without intermediate optical elements, e.g. fibres with plane ends, fibres with shaped ends, bundles
• CPC Class Codes: G02B 6/4204 the coupling comprising intermediate optical elements, e.g. lenses, holograms encapsulated active devices H01S5/02208, H01L33/52
• CPC Class Codes: H01S 5/101 Curved waveguide H01S5/1243 takes precedence
• CPC Class Codes: H01S 5/1014 Tapered waveguide, e.g. spotsize converter H01S5/1064 takes precedence
• CPC Class Codes: H01S 5/34 comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers H01S5/36 takes precedence
• CPC Class Codes: H01S 5/5018 using two or more amplifiers or multiple passes through the same amplifier
• CPC Class Codes: H04J 14/0226 Fixed carrier allocation, e.g. according to service
• CPC Class Codes: H04J 14/0246 using one wavelength per ONU
• CPC Class Codes: H04J 14/0247 Sharing one wavelength for at least a group of ONUs
• 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 14/0252 Sharing one wavelength for at least a group of ONUs, e.g. for transmissions from-ONU-to-OLT or from-ONU-to-ONU
• CPC Class Codes: H04J 14/0282 WDM tree architectures
• CPC Class Codes: H04J 2014/0253 Allocation of downstream wavelengths for upstream transmission

Abstract

A Reflective Semiconductor Optical Amplifier (RSOA) for compensating for light loss in an optical link, an RSOA module for improving polarization dependency using the RSOA, and a Passive Optical Network (PON) for increasing economical efficiency and practical use of a bandwidth using the RSOA are provided. The PON includes a central office comprising a plurality of optic sources transmitting a downstream signal and a plurality of first receivers receiving an upstream signal; at least one optical network terminal (ONT) including a second receiver receiving the downstream signal and an RSOA which receives the downstream signal, remodulates the downstream signal into the upstream signal, and transmits the upstream signal in loopback mode; and a remote node interfacing the central office with the ONT. The upstream signal and the downstream signal are transmitted between the remote node and the ONT via a single optical fiber. The remote node includes an optical power splitter at its port connected to the ONT.

Claims

1. A passive optical network (PON) using a reflective semiconductor optical amplifier (RSOA), the PON comprising:

a central office comprising a plurality of optic sources transmitting a downstream signal to at least one optical network terminal (ONT) and a plurality of first receivers receiving an upstream signal sent from the at least one ONT;

the at least one optical network terminal (ONT) comprising a second receiver receiving the downstream signal transmitted from the central office and an RSOA which receives the downstream signal transmitted from the central office,

wherein the RSOA remodulates the downstream signal transmitted from the central office into the upstream signal for transmitting to the central office, and

transmits the remodulated upstream signal to the central office in loopback mode; and

a remote node interfacing the central office with the ONT,

wherein the upstream signal transmitted to the central office from the ONT, which has been remodulated by the RSOA after receiving the downstream signal sent from the central office to the ONT and the downstream signal transmitted from the central office to the ONT prior to being remodulated are transmitted between the remote node and the ONT via a single optical fiber.

2. The PON of claim 1, wherein input/output ports of the second receiver and the RSOA are combined through a coupler.

3. The PON of claim 1, wherein the upstream signal and the downstream signal are transmitted via different optical fibers, respectively, between the central office and the remote node.

4. The PON of claim 3, wherein the remote node comprises an optical multiplexer/demultiplexer and a circulator.

5. The PON of claim 1, wherein the upstream signal and the downstream signal are transmitted between the central office and the remote node via a single optical fiber.

6. The PON of claim 5, wherein the remote node comprises an optical multiplexer/demultiplexer, and the central office comprises a circulator, an optical multiplexer, and an optical demultiplexer.

7. The PON of claim 1, wherein the remote node comprises:

an optical multiplexer/demultiplexer; and

an optical power splitter installed at a port of the optical multiplexer/demultiplexer to be connected to the ONT.

8. The PON of claim 7, wherein the optical power splitter has a split ratio of 1:

M and accommodates M ONTs.

9. The PON of claim 7, wherein the optical power splitter is used to employ time division multiplexing (TDM), the second receiver extracts a signal from a time slot assigned thereto, and the RSOA inserts a signal into a time slot assigned thereto.

10. The PON of claim 7, wherein the first receiver is a burst mode receiver.

11. The PON of claim 7, wherein the central office further comprises:

an optical amplifier connected to an output end of an optical multiplexer connected to output ends of the respective optic sources.

12. The PON of claim 11, wherein the optical amplifier is an erbium-doped fiber amplifier (EDFA).