WO2000021164A1 - Ultra-wide bandwidth fiber based optical amplifier - Google Patents
Ultra-wide bandwidth fiber based optical amplifier Download PDFInfo
- Publication number
- WO2000021164A1 WO2000021164A1 PCT/US1999/023094 US9923094W WO0021164A1 WO 2000021164 A1 WO2000021164 A1 WO 2000021164A1 US 9923094 W US9923094 W US 9923094W WO 0021164 A1 WO0021164 A1 WO 0021164A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- amplifier
- bandwidth
- optical
- amplifier block
- fiber
- Prior art date
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Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
- H01S3/06—Construction or shape of active medium
- H01S3/063—Waveguide lasers, i.e. whereby the dimensions of the waveguide are of the order of the light wavelength
- H01S3/067—Fibre lasers
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
- G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
- G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
- G02B6/29304—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by diffraction, e.g. grating
- G02B6/29316—Light guides comprising a diffractive element, e.g. grating in or on the light guide such that diffracted light is confined in the light guide
- G02B6/29317—Light guides of the optical fibre type
- G02B6/29319—With a cascade of diffractive elements or of diffraction operations
- G02B6/2932—With a cascade of diffractive elements or of diffraction operations comprising a directional router, e.g. directional coupler, circulator
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
- H01S3/13—Stabilisation of laser output parameters, e.g. frequency or amplitude
- H01S3/131—Stabilisation of laser output parameters, e.g. frequency or amplitude by controlling the active medium, e.g. by controlling the processes or apparatus for excitation
- H01S3/1312—Stabilisation of laser output parameters, e.g. frequency or amplitude by controlling the active medium, e.g. by controlling the processes or apparatus for excitation by controlling the optical pumping
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/14—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range characterised by the material used as the active medium
- H01S3/16—Solid materials
- H01S3/1601—Solid materials characterised by an active (lasing) ion
- H01S3/1603—Solid materials characterised by an active (lasing) ion rare earth
- H01S3/1608—Solid materials characterised by an active (lasing) ion rare earth erbium
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/23—Arrangements of two or more lasers not provided for in groups H01S3/02 - H01S3/22, e.g. tandem arrangements of separate active media
- H01S3/2383—Parallel arrangements
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B2210/00—Indexing scheme relating to optical transmission systems
- H04B2210/25—Distortion or dispersion compensation
- H04B2210/258—Distortion or dispersion compensation treating each wavelength or wavelength band separately
Definitions
- the present invention relates to optical amplifiers, and more particularly relates to an ultra-wide bandwidth fiber based optical amplifier which divides the erbium wavelength band (1520 nm - l ⁇ lOnm) into three separate bands, separately amplifies each of the three bands in parallel configuration, and then recombines the bands to provide uniform gain flatness over the entire bandwidth.
- Background art The design of wavelength division multiplexed (WDM) systems in the 1550nm range is currently constrained by the limited bandwidth available from conventional erbium doped fiber amplifiers. The presently available bandwidth is limited to about 20nm because of the highly structured gain spectrum of conventional erbium doped fibers.
- gain equalization filters can extend the usable bandwidth up to about 40nm (about 1525nm to about 1565nm) .
- This 40nm gain spectrum allows the use of more channels in a WDM system.
- proposed 10 Gb/s systems will require the use of the entire 80-90 nm bandwidth with very small channel spacings .
- One possible solution to provide greater bandwidth would be to provide an erbium doped fiber that has a gain spectrum over a greater bandwidth. This would allow a single fiber amplifier to provide a gain spectrum over a greater bandwidth.
- Erbium doped fluoride fibers have shown gain spectrums of 25nm without gain equalization filters, and newer, tellurite erbium doped fibers have gain spectrums in different ranges, but the gains are highly non- uniform. To date, it has been impossible to provide a single erbium doped fiber which has a uniform gain spectrum over more than a 25nm bandwidth. Another proposed solution is to divide the erbium bandwidth into two bands and separately amplify the separated bands in parallel configuration. This concept allows the use of two different amplifiers which can be optimized for a flat gain region within a specific band. This solution was proposed in the April 10, 1997 publication of Electronics Letters (Vol. 33. No. 8) .
- the article describes a broadband amplifier which divides the available bandwidth into two bands, a 1520nm- 1570nm band (1.55Dm band) and a 1570nm - 1610nm band (1.58Dm band).
- the configuration of each band is based on a cascade configuration with a 980nm pumped EDFA and a 1480nm pumped EDFA using a combination of silica and fluoride fibers to optimize gain flatness.
- the EDFA unit for the 1.55Dm band showed a relatively flat gain spectrum from 1530nm - 1560nm
- the EDFA unit for the 1580nm band showed a relatively flat gain spectrum from 1576nm - l ⁇ OOnm.
- the optical channels are split into two bands, a C-band with a range of 152Onm - 1570nm and an L-band with a range of 1570nm - 1620nm.
- the C-band branch has a single stage amplifier, while the L-band branch has a two stage amplifier.
- the gam bandwidth in the C- band was shown to be 36.9nm while the gam bandwidth in the L-band was shown to be 43.4nm giving a total gain bandwidth of 80.3nm. While the system demonstrates an even greater gam spectrum, the gam spectrum in both the C-band and L-band are non-uniform which makes real-life utilization of the entire gain spectrum difficult.
- the present invention seeks to solve the prior art shortcomings by dividing the erbium wavelength band into three separate bandwidths, 1520nm - 1541nm (Cl band), 1541-1565 (C2 band) and 1565-1610 (L band) and separately amplifying each bandwidth with a specially designed amplifier block optimized to provide a flat ga spectrum within the limited bandwidth.
- the amplifier then recombines the separately amplified band to provide an ultra-wide bandwidth amplifier with a flat gam spectrum over the entire 90nm bandwidth.
- the concept of splitting the C band into two separate bands may seem controversial at first since it clearly adds complexity where none would seem to be needed. However, it will be shown herein that there are significant advantages to be found in this approach.
- each of the three bands is significantly different, and these differences have many subtle effects on gam, noise figures, output power, saturation/inversion conditions, and required pumping power.
- the lower limit of the Cl band can be broadened to include 1520nm with the proper choice of glass host, thus gaining up to 5nm of bandwidth and compensating for channels lost at the intersection of the Cl and C2 bands.
- the Cl band there is an inherent gam peak at 1530nm. Eliminating this peak becomes much easier with a total Cl bandwidth of 20nm versus 35nm for the conventional (1525-1565nm) C bandwidth.
- the present invention also addresses the challenges of separating and then efficiently recomb ing multiple wavelength bands, which typically causes a dip in gain at the intersection of the two bands and also causes multi-path interference (MPI) .
- MPI multi-path interference
- the problem is resolved by constructing all three amplifier blocks with the same optical transmission length.
- the Cl and C2 band amplifier blocks which include shorter erbium doped fibers than the L band amplifier block, are physically lengthened using lengths of single mode fiber so that the total length of the optical transmission path of each amplifier block is generally equal. Fiber lengths are controlled to within 500 microns.
- Selected amplifier blocks further include delay control devices which selectively delay signals passing through the respective amplifier block to provide further fine adjustment to signal recombination. More specifically, the wide bandwidth optical amplifier of the present invention includes first, second and third amplifier blocks.
- a demultiplexer device splits the 1550nm wavelength band into first (Cl), second (C2) and third (L) bandwidths, and outputs the respective bandwidths to the input ends of the first, second and third amplifier blocks.
- the first bandwidth (Cl) has a range from about 1520nm to about 1541nm
- the second bandwidth (C2) has a range from about 1541nm to about 1565nm
- the third bandwidth (L) has a range from about 1565nm to about 1610nm.
- a demultiplexer multiplexer connected to the output ends of the first, second and third amplifier blocks recombines the first, second and third bandwidths after being amplified.
- Each of the amplifier blocks includes an optical amplifier assembly constructed and arranged for amplifying the respective bandwidth with a substantially flat gam profile.
- Pump input for each of the amplifier blocks is provided by a pump laser which delivers high pump power (.5W) into a single mode fiber.
- a pump laser which delivers high pump power (.5W) into a single mode fiber.
- Existing erbium fiber designs allow the gam profile of the C2 band to have a ga flatness of ⁇ ldB with a 25dB gam.
- the Cl band amplifier block and the L band amplifier block each utilize a gain equalization filter to provide about the same gain and flatness.
- Each of the amplifier blocks further implements an automatic gain control system which maintains constant gain for each channel, irrespective of variations in input power and number of channels.
- Each amplifier block is constructed to have the same optical transmission path length regardless of the different lengths of the erbium doped fibers required for optical amplification m each block.
- the L band erbium fiber is significantly longer than the erbium fibers required for either of the Cl and C2 bands. Since the L band has the longest erbium doped fiber it is used as the basis for the standard length of the optical transmission path.
- the optical transmission lengths of the Cl and C2 band amplifier blocks are lengthened using lengths of single mode fiber spliced into the amplifier block. These lengths of single mode fiber allow the lengths of the optical transmission paths of the Cl and C2 bands to roughly approximately the length of the optical transmission path of the L band.
- MPI is further reduced by the use of delay control devices, such as piezoelectric distance controls, fiber stretchers, and lithium niobate crystals, in the Cl and L amplifier blocks to selectively delay signals passing through these amplifier blocks.
- delay control devices such as piezoelectric distance controls, fiber stretchers, and lithium niobate crystals
- the use of these highly sensitive and selectively controllable delay devices will permit operators to fine tune wavelength recombination and reduce MPI .
- an ultra-wide bandwidth fiber based optical amplifier having a flat gain spectrum over the entire 1520nm - 1610nm bandwidth; the provision of such an amplifier which minimizes multi-path interference (MPI); the provision of such an amplifier which provides a wideband gain of >25dB per channel; the provision of such an amplifier which has consistent low noise of ⁇ 6dB across the entire band; the provision of such an amplifier having a gain flatness of ⁇ ldbB for all useful channels; the provision of such an amplifier having an automatic gain control; and the provision of such an amplifier having modular components for enhanced field serviceability and upgradeability.
- MPI multi-path interference
- Fig. 1 is a general schematic illustration of the ultra-wide bandwidth fiber based optical amplifier of the present invention
- Fig. 2 is a detailed schematic illustration thereof
- Fig. 3 is a schematic illustration of the demultiplexer device. Description of the Preferred Embodiment: Referring now to the drawings, the ultra-wide bandwidth fiber based optical amplifier of the instant invention is illustrated and generally indicated at 10 n Figs. 1-2.
- the present invention seeks to solve the prior art shortcomings by dividing the erbium wavelength band into three separate bandwidths, 1520nm - 1541nm (Cl band), 1541-1565 (C2 band) and 1565-1610 (L band) and separately amplifying each bandwidth with a specially designed amplifier block optimized to provide a flat gain spectrum within the limited bandwidth.
- the amplifier 10 then recombines the separately amplified band to provide an ultra-wide bandwidth amplifier with a flat gain spectrum over the entire 90nm bandwidth.
- the wide bandwidth optical amplifier 10 comprises first, second and third amplifier blocks, each generally indicated at 12, 14 and 16.
- the first bandwidth (Cl) has a range from about 1520nm to about 1541nm
- the second bandwidth (C2) has a range from about 1541nm to about 1565nm
- the third bandwidth (L) has a range from about 1565nm to about 1610nm.
- a multiplexer device generally indicated at 20 connected to the output ends of the first, second and third amplifier blocks 12, 14, 16 recombines the first, second and third bandwidths after being amplified. Referring to Fig.
- the demultiplexer and multiplexer devices 18, 20 are not conventional multiplexing devices, but rather the devices 18, 20 are comprised of coupled optical circulators 22, 24.
- the demultiplexer device 18 is illustrated in detail in Fig. 3.
- the entire bandwidth 1520nm to 1610nm is fed into a first leg 26 of the first optical circulator 22.
- the second leg 28 of the circulator 22 is connected to a first leg 30 of the second optical circulator 24.
- This second leg 28 is provided with a wideband chirped Bragg grating 32 for reflecting the Cl band back through the first circulator 22.
- the reflected Cl band travels back through the first circulator 22 and is output on the third leg 34 of the first circulator 22 to the first amplifier block 12.
- the Bragg grating 32 allows the C2 and L bands to pass through to the second circulator 24 where these bands circulate to the second leg 36 which is provided with a wideband chirped Bragg grating 38 for reflecting the L band.
- the C2 band is allowed to pass through the second leg 36 for output to the second amplifier block 14.
- the L band travels back through the second circulator 24 and is output on the third leg 40 of the second circulator 24 to the third amplifier block 16.
- the Bragg gratings 32 and 38 must have a reflectivity of greater than 80%, and more preferably greater than 95%.
- the multiplexer device 20 operates in reverse fashion to recombine the Cl, C2 and L bands.
- the demultiplexed Cl band is received into the first amplifier block 12 and fed into the input end of a wavelength division multiplexer (WDM) 42.
- the first amplifier block 12 is optimized for amplifying the Cl band, and in this regard, the block 12 includes an erbium doped silica fiber (EDF1) 44 having a high concentration of aluminum of up to 6% by weight, and a length of between about 5m to about 20m, the actual length depending on the erbium doping concentration.
- the fiber 44 is optimized to provide a small signal ga of between 30 and 40 dB.
- the erbium doped fiber 44 is coupled to the output end of the WDM 42, and is pumped by a high power, optically pumped semiconductor pump laser 46.
- the laser 46 has a single spatial mode and delivers high pump power (.5W) into the single mode fiber.
- the pump signal is also fed into an input of the WDM 42 where it is combined with the existing signal to be amplified.
- Pump lasers 46 of the type contemplated are commercially available.
- Output from the erbium doped fiber 44 is passed through a gam equalization filter 48, such as a dielectric coating, or long period grating, to provide a gam flatness of less than ldB.
- the C2 band is received into the second amplifier block 14 and fed into the input end of another wavelength division multiplexer (WDM) 50.
- WDM wavelength division multiplexer
- the second amplifier block 14 is optimized for amplifying the C2 band and in th s regard includes an erbium doped silica fiber (EDF2) 52 having a medium concentration of aluminum of up to 4% by weight, and a length of between about 5m to about 20m, preferably about 10m, but again the actual length depending on the erbium doping concentration.
- EDF2 erbium doped silica fiber
- Existing erbium fiber designs for this wavelength range allow the gam profile of the C2 band to have a gain flatness of ⁇ ldB with a 25dB gam could be used for this application without the further use of any external gain equalization filters, whereas, the Cl band amplifier block and the L band amplifier block each utilize a ga equalization filter to provide about the same gam and flatness.
- the erbium doped fiber 52 is coupled to the output end of the WDM 50, and is pumped by a high power optically pumped semiconductor pump laser 54 as described heremabove.
- the L band is received into the third amplifier block 16 and fed into the input end of yet another wavelength division multiplexer (WDM) 56.
- the third amplifier block 16 is optimized for amplifying the L band and in this regard includes an erbium doped silica fiber (EDF3) 58 having a concentration of aluminum of up to 6% by weight and a length of between about 40m to about 200m, the fiber length being scaled to the erbium doping concentration.
- the fiber 58 is optimized to provide a gam of about 25dB w th a gain flatness of less than 5dB.
- the erbium doped fiber 58 is coupled to the output end of the WDM 56, and is pumped by a high power optically pumped semiconductor pump laser 60 as described heremabove.
- the pump signal is also fed into an input of the WDM 56 where it is combined with the existing signal to be amplified.
- Output from the erbium doped fiber 58 is passed through a gam equalization filter 62 to provide a gam flatness of less than ldB.
- Each of the amplifier blocks 12, 14, 16 further include automatic gain control systems, generally indicated at 64, 66, and 68 respectively, which maintain constant gam for each channel, irrespective of variations in input power and number of channels.
- Each of the gam control systems 64, 66, 68 includes a gam control circuit 64A, 66A, 68A, an input tap 64B, 66B, 68B (fused fiber coupler with 1% tap), and an output tap 64C, 66C, 68C (fused fiber coupler with 1% tap) .
- the input taps 64B, 66B, 68B are located in the path between the demultiplexer 18 and the respective WDM whereby they tap the preamplified signal input directly from the demultiplexer 18.
- the output taps 64C, 66C, 68C are located in the paths after the erbium doped fibers whereby they tap the amplified signal.
- each amplifier block 12, 14, 16 is constructed to have the same optical transmission path length regardless of the different lengths of the erbium doped fibers 44, 52, 58 required for optical amplification in each block.
- the L band erbium fiber 58 is significantly longer (100m) than the erbium fibers 44, 52 required for either of the Cl and C2 bands (15m) .
- the optical transmission lengths of the Cl and C2 band amplifier blocks are each lengthened using a respective length of single mode fiber 70, 72 spliced into the respective amplifier block 12, 14.
- the length of the single mode fibers 70, 72 can range from 5 - 100m depending on the length of the L band amplifier block.
- the length of the single mode extension fiber 70 for the first amplifier block is about 15m
- the length of the single mode extension fiber 72 for the second amplifier block s also about 15m.
- Fine tuning of the optical transmission path length is accomplished by the use of additional delay control devices 74, 76, inserted respectively into each of the Cl and L amplifier blocks to selectively delay signals passing through these amplifier blocks 12, 16.
- Delay control devices of the type contemplated herein include piezoelectric distance controls, fiber stretchers, and lithium niobate crystals, as well as other known, and as yet unknown devices for delaying signals in an optical fiber.
- the delay controls 74, 76 comprise piezoelectric fiber stretchers which are commonly available in the industry. The use of these highly sensitive and selectively controllable delay devices permit fine tuning of the wavelength recombination and substantially reduce, or eliminate MPI.
- the approach described herein combines a known technologies with further experimental technologies to provide an optical amplifier having over 90nm of available bandwidth.
- the use of high power pump lasers allows for an increased number of channels, without reduction m power per channel.
- the use of additional lengths of single mode fibers in the Cl and C2 amplifier blocks and the further use of delay control devices minimizes and/or eliminates multi-path interference (MPI) when recombining the bandwidths.
- MPI multi-path interference
- the optimized amplifier blocks cooperate to provide a wideband ga of 25 to 40 dB per channel with a consistent low noise of ⁇ 6dB across the entire band, and gam flatness of ⁇ ldB for all useful channels.
- An automatic gam control provides for uniform gam during operation.
Abstract
Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2000575190A JP2002527891A (en) | 1998-10-05 | 1999-10-05 | Ultra-wide bandwidth fiber-based optical amplifier |
EP99954737A EP1127391A1 (en) | 1998-10-05 | 1999-10-05 | Ultra-wide bandwidth fiber based optical amplifier |
CA002346411A CA2346411A1 (en) | 1998-10-05 | 1999-10-05 | Ultra-wide bandwidth fiber based optical amplifier |
AU11015/00A AU1101500A (en) | 1998-10-05 | 1999-10-05 | Ultra-wide bandwidth fiber based optical amplifier |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10307798P | 1998-10-05 | 1998-10-05 | |
US60/103,077 | 1998-10-05 |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2000021164A1 true WO2000021164A1 (en) | 2000-04-13 |
WO2000021164A9 WO2000021164A9 (en) | 2000-09-08 |
Family
ID=22293255
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1999/023094 WO2000021164A1 (en) | 1998-10-05 | 1999-10-05 | Ultra-wide bandwidth fiber based optical amplifier |
Country Status (5)
Country | Link |
---|---|
EP (1) | EP1127391A1 (en) |
JP (1) | JP2002527891A (en) |
AU (1) | AU1101500A (en) |
CA (1) | CA2346411A1 (en) |
WO (1) | WO2000021164A1 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2002039552A2 (en) * | 2000-11-09 | 2002-05-16 | Nortel Networks Limited | Optical amplifier method and apparatus |
US6424459B1 (en) * | 1999-07-07 | 2002-07-23 | Fujitsu Limited | Gain-flattening of an optical amplifier with split-band architecture |
WO2004075363A1 (en) * | 2003-02-20 | 2004-09-02 | Fujitsu Limited | Method and system for optical transmission |
DE102006006550A1 (en) * | 2006-02-13 | 2007-08-23 | Siemens Ag | Method and arrangement for reducing spectral hole burning |
WO2014129613A1 (en) * | 2013-02-25 | 2014-08-28 | カナレ電気株式会社 | Optical amplifier and laser oscillator |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4725951B2 (en) * | 2004-07-28 | 2011-07-13 | 富士通株式会社 | Wavelength multiplexed signal light amplification method and optical amplifier |
JP2012114235A (en) * | 2010-11-24 | 2012-06-14 | Nippon Telegr & Teleph Corp <Ntt> | Optical amplifier and optical amplification method |
US9998806B2 (en) | 2016-11-10 | 2018-06-12 | Google Llc | Overlapping spectrum amplification |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5659644A (en) * | 1996-06-07 | 1997-08-19 | Lucent Technologies Inc. | Fiber light source with multimode fiber coupler |
-
1999
- 1999-10-05 EP EP99954737A patent/EP1127391A1/en not_active Withdrawn
- 1999-10-05 WO PCT/US1999/023094 patent/WO2000021164A1/en not_active Application Discontinuation
- 1999-10-05 AU AU11015/00A patent/AU1101500A/en not_active Abandoned
- 1999-10-05 CA CA002346411A patent/CA2346411A1/en not_active Abandoned
- 1999-10-05 JP JP2000575190A patent/JP2002527891A/en active Pending
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5659644A (en) * | 1996-06-07 | 1997-08-19 | Lucent Technologies Inc. | Fiber light source with multimode fiber coupler |
Non-Patent Citations (3)
Title |
---|
OHISHI Y. ET AL: "Optical fiber amplifiers for WDM transmission", NTT REVIEW, vol. 10, no. 1, January 1998 (1998-01-01), pages 45 - 51, XP000729758 * |
YAMADA M. ET AL: "Broadband and gain-flattened amplifier composed of a 1.55mum-band Er3+-doped fibre amplifier in a parallel configuration", ELECTRONICS LETTERS, vol. 33, no. 8, 10 April 1997 (1997-04-10), pages 710 - 711, XP000901169 * |
YAMADA M. ET AL: "Ultra-broadband and gain-flattened EDFAs for WDM signals", OSA A TRENDS IN OPTICS AND PHOTONICS SERIES, vol. 16, 23 July 1997 (1997-07-23), pages 14 - 29, XP000901275 * |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6424459B1 (en) * | 1999-07-07 | 2002-07-23 | Fujitsu Limited | Gain-flattening of an optical amplifier with split-band architecture |
WO2002039552A2 (en) * | 2000-11-09 | 2002-05-16 | Nortel Networks Limited | Optical amplifier method and apparatus |
WO2002039552A3 (en) * | 2000-11-09 | 2002-12-27 | Nortel Networks Ltd | Optical amplifier method and apparatus |
WO2004075363A1 (en) * | 2003-02-20 | 2004-09-02 | Fujitsu Limited | Method and system for optical transmission |
DE102006006550A1 (en) * | 2006-02-13 | 2007-08-23 | Siemens Ag | Method and arrangement for reducing spectral hole burning |
WO2014129613A1 (en) * | 2013-02-25 | 2014-08-28 | カナレ電気株式会社 | Optical amplifier and laser oscillator |
Also Published As
Publication number | Publication date |
---|---|
EP1127391A1 (en) | 2001-08-29 |
JP2002527891A (en) | 2002-08-27 |
AU1101500A (en) | 2000-04-26 |
WO2000021164A9 (en) | 2000-09-08 |
CA2346411A1 (en) | 2000-04-13 |
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