WO1998016018B1 - Wavelength division multiplexed signal amplifier - Google Patents
Wavelength division multiplexed signal amplifierInfo
- Publication number
- WO1998016018B1 WO1998016018B1 PCT/US1997/018339 US9718339W WO9816018B1 WO 1998016018 B1 WO1998016018 B1 WO 1998016018B1 US 9718339 W US9718339 W US 9718339W WO 9816018 B1 WO9816018 B1 WO 9816018B1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- noise
- amplifier
- signals
- signal
- channels
- Prior art date
Links
- 230000003287 optical Effects 0.000 claims abstract 6
- 238000001914 filtration Methods 0.000 claims 6
- 238000009738 saturating Methods 0.000 claims 3
- 230000002269 spontaneous Effects 0.000 claims 3
- 230000005540 biological transmission Effects 0.000 claims 1
- 238000004519 manufacturing process Methods 0.000 claims 1
- 238000003672 processing method Methods 0.000 abstract 1
- 231100000486 side effect Toxicity 0.000 abstract 1
Abstract
An optical signal processing method and apparatus for providing a noise feedback loop that uses existing noise within the optical system to saturate a chain of amplifiers after the branching unit, thereby preventing information channels in a WDM signal containing empty channels from becoming overamplified as they pass through downstream amplifiers. The method and apparatus uses an existing drop amplifier (42) which emits ASE noise as a side effect. A coupler (40) connects the ASE noise to a filter (38). The filtered ASE noise is fed into an existing trunk amplifier (32) by a second coupler (36). The trunk amplifier increases gain to the filtered ASE noise to a level high enough to saturate the amplifier chain, without requiring an external noise generating device.
Claims
1. An apparatus for using filtered noise to saturate an amplifier chain when new data is added to a WDM signal, comprising:
a first amplifier emitting noise;
a coupler connected to said first amplifier for directing the noise away from said first amplifier;
a filter connected to said coupler for filtering the noise directed by said coupler from said first amplifier; and
a second amplifier connected to said filter for amplifying the noise thereby saturating the amplifier chain.
2. An apparatus for adding noise to a multiplexed signal having a plurality of channels, comprising: a first amplifier generating a noise signal and having a first amplifier output; a filter having a filter input coupled to said first amplifier output, said filter receiving and filtering said noise signal, and having a filter output; a second amplifier having a second amplifier input coupled to said filter output, said second amplifier receiving and amplifying said filtered noise signal, and having a second amplifier output; and an add/drop multiplexer (ADM) having an ADM input coupled to said second amplifier output, said ADM receiving said amplified noise signal and combining an information signal with said amplified noise signal.
3. The apparatus of claim 1, wherein the multiplexed signal is a wavelength division multiplexed 10
signal .
4. The apparatus of claim 3 , wherein said noise signal is spontaneous emission noise.
5. The apparatus of claim 4, wherein said filter is a bandpass filter.
6. The apparatus of claim 5, wherein said bandpass filter filters said noise signals within a gain pass band matching said second amplifier and out of a band for the plurality of channels.
7. The apparatus of claim 5, wherein said ADM comprises: a demultiplexer demultiplexing the noise signal into separate channels; a drop line dropping a first channel of noise signals; an add line adding information signals to said first channel; and a multiplexer multiplexing said demultiplexed channels together.
8. The apparatus of claim 5, further comprising a third amplifier amplifying the combined signal without saturating said information signals carried on said first channel of said combined signal.
9. A method for producing a noise-filled signal, comprising the steps of: generating noise signals; filtering said noise signals; amplifying said filtered noise signals; and combining said filtered noise signals with information signals. 11
10. The method of claim 9, wherein said step of combining comprises the steps of: demultiplexing said amplified noise signals into a plurality of channels; dropping noise signals from a first channel; adding information signals to said first channel; and multiplexing said channels together.
11. The method of claim 10, wherein said steps of demultiplexing and multiplexing comprise the steps of wavelength division demultiplexing and wavelength division multiplexing.
12. The method of claim 9 , wherein said step of generating comprises the steps of: receiving a null signal; amplifying said null signal; and gathering backward emission noise created by amplifying said null signal.
13. The method of claim 9 , wherein said backward emission noise is created by amplified spontaneous emissions.
14. The method of claim 9, wherein said step of filtering filters said noise signals within a gain pass band and out of an information pass band for said plurality of channels.
15. The method of claim 10, further comprising the step of amplifying the combined signals without saturating said information signals carried on said first channel.
16. An optical bit stream created by the steps of: 12
generating noise signals; filtering said noise signals; amplifying said filtered noise signals; and combining said amplified noise signals with information signals.
17. The optical bit stream of claim 16, wherein said step of combining comprises: demultiplexing said amplified noise signals into a plurality of channels; dropping noise signals from a first channel; adding information signals to said first channel; and multiplexing said channels together.
18. In an optical transmission system, an apparatus for producing an optical signal having a plurality of channels, with a first set of channels having noise signals and a second set of channels having information signals, comprising: a first amplifier generating backward spontaneous emission noise signals; a filter coupled to said first amplifier for filtering said noise signals; a second amplifier coupled to said filter for amplifying said noise signals; and an add/drop multiplexer coupled to said second amplifier for combining said amplified noise signals with information signals.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AU47531/97A AU4753197A (en) | 1996-10-10 | 1997-10-09 | Method and apparatus for saturating an optical amplifier chain to prevent ov er amplification of a wavelength division multiplexed signal |
| CA2268005A CA2268005C (en) | 1996-10-10 | 1997-10-09 | Wavelength division multiplexed signal amplifier |
| EP97910063A EP0943192B1 (en) | 1996-10-10 | 1997-10-09 | Method and apparatus for saturating an optical amplifier chain to prevent over amplification of a wavelength division multiplexed signal |
| DE69737505T DE69737505T2 (en) | 1996-10-10 | 1997-10-09 | Method and apparatus for saturating an optical amplification chain to prevent the overmodulation of a wavelength-multiplexed signal |
| JP10517776A JP2001502143A (en) | 1996-10-10 | 1997-10-09 | Method and apparatus for saturating an optical amplifier chain to avoid over-amplification of a wavelength division multiplexed signal |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US08/728,651 | 1996-10-10 | ||
| US08/728,651 US5719697A (en) | 1996-10-10 | 1996-10-10 | Method and apparatus for combining add/drop optical signal lines from a plurality of branching units |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| WO1998016018A2 WO1998016018A2 (en) | 1998-04-16 |
| WO1998016018A3 WO1998016018A3 (en) | 1998-06-04 |
| WO1998016018B1 true WO1998016018B1 (en) | 1998-07-09 |
Family
ID=24927729
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/US1997/018339 WO1998016018A2 (en) | 1996-10-10 | 1997-10-09 | Wavelength division multiplexed signal amplifier |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US5719697A (en) |
| EP (1) | EP0943192B1 (en) |
| JP (1) | JP2001502143A (en) |
| AU (1) | AU4753197A (en) |
| CA (1) | CA2268005C (en) |
| DE (1) | DE69737505T2 (en) |
| TW (1) | TW444454B (en) |
| WO (1) | WO1998016018A2 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2347809B (en) * | 1999-03-12 | 2001-06-20 | Marconi Comm Ltd | Signal transmission system |
| US20010046350A1 (en) * | 2000-02-25 | 2001-11-29 | Tedesco James M. | Configurable Wavelength routing device |
| JP3970594B2 (en) * | 2001-12-05 | 2007-09-05 | 日本電気通信システム株式会社 | Optical multiplexing / demultiplexing system |
| US7444078B1 (en) * | 2003-09-18 | 2008-10-28 | At&T Intellectual Property Ii, L.P. | Transient control solution for optical networks |
| US7526201B2 (en) * | 2004-06-25 | 2009-04-28 | Tyco Telecommunications (Us) Inc. | Optical fiber transmission system with noise loading |
| US9020353B2 (en) * | 2009-10-16 | 2015-04-28 | Nec Corporation | Optical branching unit, optical communication system, and optical multiplexing method |
| US9509113B2 (en) * | 2014-06-17 | 2016-11-29 | Fujitsu Limited | Transient gain cancellation for optical amplifiers |
| US11569907B2 (en) * | 2020-08-26 | 2023-01-31 | Ciena Corporation | Per-band fault signaling in a multi-band optical transmission system |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2787820B2 (en) * | 1990-07-20 | 1998-08-20 | キヤノン株式会社 | WDM optical communication system and optical amplifier used therein |
| US5128800A (en) * | 1991-06-19 | 1992-07-07 | At&T Bell Laboratories | Gain switchable optical fiber amplifier |
| GB2280561B (en) * | 1993-07-31 | 1997-03-26 | Northern Telecom Ltd | Optical transmission system |
| FR2720883B1 (en) * | 1994-06-07 | 1997-01-10 | Cit Alcatel | Optical spectral insertion-extraction multiplexer. |
| KR0146648B1 (en) * | 1994-06-28 | 1998-08-17 | 양승택 | Optical transmission system |
| JP2723067B2 (en) * | 1995-03-14 | 1998-03-09 | 日本電気株式会社 | Optical amplifier |
-
1996
- 1996-10-10 US US08/728,651 patent/US5719697A/en not_active Expired - Lifetime
-
1997
- 1997-10-09 AU AU47531/97A patent/AU4753197A/en not_active Abandoned
- 1997-10-09 CA CA2268005A patent/CA2268005C/en not_active Expired - Fee Related
- 1997-10-09 JP JP10517776A patent/JP2001502143A/en not_active Ceased
- 1997-10-09 EP EP97910063A patent/EP0943192B1/en not_active Expired - Lifetime
- 1997-10-09 DE DE69737505T patent/DE69737505T2/en not_active Expired - Lifetime
- 1997-10-09 WO PCT/US1997/018339 patent/WO1998016018A2/en active IP Right Grant
- 1997-10-09 TW TW086114864A patent/TW444454B/en not_active IP Right Cessation
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