WO1999043118A1 - Mrl dense dans la bande 1310nm - Google Patents

Mrl dense dans la bande 1310nm Download PDF

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Publication number
WO1999043118A1
WO1999043118A1 PCT/US1999/003573 US9903573W WO9943118A1 WO 1999043118 A1 WO1999043118 A1 WO 1999043118A1 US 9903573 W US9903573 W US 9903573W WO 9943118 A1 WO9943118 A1 WO 9943118A1
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WO
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Prior art keywords
dispersion
subband
fiber
approximately
guardband
Prior art date
Application number
PCT/US1999/003573
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English (en)
Inventor
Joseph C. Cook
Xiaoping C. Mao
Original Assignee
Mci Worldcom, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US09/106,725 external-priority patent/US6043914A/en
Application filed by Mci Worldcom, Inc. filed Critical Mci Worldcom, Inc.
Priority to JP2000532943A priority Critical patent/JP2002504777A/ja
Priority to MXPA00008183A priority patent/MXPA00008183A/es
Priority to CA002321500A priority patent/CA2321500A1/fr
Priority to EP99913813A priority patent/EP1053614A4/fr
Publication of WO1999043118A1 publication Critical patent/WO1999043118A1/fr

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/25—Arrangements specific to fibre transmission
    • H04B10/2507—Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion
    • H04B10/2513—Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to chromatic dispersion
    • H04B10/25133—Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to chromatic dispersion including a lumped electrical or optical dispersion compensator
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • 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
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0224—Irregular wavelength spacing, e.g. to accommodate interference to all wavelengths

Definitions

  • the present invention relates to fiber optic networks and multi- channel communication systems.
  • Modern communication systems increasingly rely upon fiber optic networks to carry increasing amounts of data between sites.
  • the use of multiple optical carriers, also called channels, over the same optical fiber increases capacity.
  • Wavelength division multiplexing (WDM) allows multiple channels to be carried on a fiber in different carrier wavelengths. Attenuation and dispersion in an optical fiber limit the distance an optical signal can travel without amplification and/or dispersion compensation.
  • WDM Wavelength division multiplexing
  • Attenuation and dispersion in an optical fiber limit the distance an optical signal can travel without amplification and/or dispersion compensation.
  • In commercial optical fibers there are two infrared wavelength windows or bands at which the fiber material offers minimal attenuation.
  • One window is generally called the "1310 nm window” and include a wavelength band between approximately 1150-1385 nm (nanometer) with a minimum loss of about 0.4 dB/km.
  • the other window includes longer wavelengths in a range between approximately 1500-1600 nm and has minimum attenuation of about 0.2 dB/km (decibel/kilometer).
  • the window between about 1520 to 1560 nm is often amplified by erbium- doped materials and thus has been called the "erbium band" or "erbium window” .
  • the telecommunication industry has focused upon devices and fibers to support operation at around 1550nm, especially in multi -channel , WDM applications.
  • the 1310 nm band was essentially abandoned as new fibers, semiconductor lasers and receivers were developed to support 1550nm WDM operation.
  • commercial systems have primarily employed the 1310nm window for single- channel communication.
  • wavelength division multiplexing In order to increase the utilization of an optical communications fiber, wavelength division multiplexing (WDM) is employed to send multiple optical carriers along the fiber, each at a different wavelength.
  • WDM wavelength division multiplexing
  • Engineers are striving to maximize the capacity of the erbium band in a communications network by putting as many wavelengths as possible onto a fiber. While two -wavelength and four-wavelength systems are fairly common, the telecommunications industry is planning for ways to crowd eight or sixteen channels at 100 GHz or 50 GHz spacing within the narrow erbium band. This presents significant challenges in transmitter stability, receiver selectivity, ease of line amplification and equalization, and avoidance of non- linear interference effects such as four-wave mixing (FWM) . Thus, only a small number of WDM channels can be effectively supported in the erbium band of an optical fiber network without sacrificing reliable, high-quality communication.
  • FWM four-wave mixing
  • a 100 Gigahertz (GHz) spacing is provided between channels to maintain signal separation and quality.
  • This 100 GHz spacing translates to a wavelength range of approximately 0.8 nm, meaning only 40 WDM channels fit within an erbium fiber band.
  • a 200 GHz spacing is preferably used between channels to avoid crosstalk.
  • only sixteen channels with 200 GHz spacing can be used effectively in an operating window within an erbium band of approximately 1530 to 1561 nm.
  • a fiber can exhibit small dispersion values only over a subset of the wavelengths available in the erbium band.
  • the dispersion effect must be compensated at intervals along the fiber to assure reliable signal reception. This further limits the number of channels which can be used in the erbium band for reliable, high-quality communication.
  • Non-Dispersion Shifted Fiber For example, such fiber has a zero-dispersion wavelength ⁇ 0 around 1312nm and a zero dispersion slope S 0 of about 0.090 ps/nm 2 -km. See e.g., CORNING®SMF- 28TM CPC6 single-mode optical fiber, Product Informa tion, 1997, pages 1 and 3. Further, the NDSF fiber can have a positive average dispersion across the erbium band. In practice, designers have been able to compensate for this by installing negative- slope fiber at intervals along an optical link.
  • NDSF Non-Dispersion Shifted Fiber
  • DSF Dispersion- Shifted Fiber
  • the capacity of fibers and fiber networks needs to be increased. Multiple channels need to be added without sacrificing the reliability and quality of voice and data communication.
  • a dense WDM window is needed in which many channels can be used to support multi -channel communication over single-mode fiber.
  • the present invention provides a method and system for dense wavelength division multiplexing (WDM) that supports multi -channel communication in the 1310nm band over a fiber link.
  • WDM dense wavelength division multiplexing
  • the dense WDM supports multi -channel communication in the 1310nm band over a single-mode fiber.
  • more channels can be added within the relatively broad 1310nm window than the erbium window, to increase the capacity of single-mode optical fibers within an optical fiber network. This avoids more expensive options for increasing capacity of a fiber optic network, such as, laying additional fiber in a network or adding channels in the crowded erbium band.
  • the present invention provides a multichannel optical communication link wherein a single- mode fiber link carries dense WDM optical signals within the 1310 nm band instead of, or in addition to, the erbium band.
  • carrier wavelengths are selected within either of two windows (a low subband and a high subband) on either side of a guardband.
  • the guardband includes a zero dispersion wavelength ⁇ 0 , which is about 1312 ⁇ 3nm for many installed and new single mode fibers in a fiber optic network.
  • the width of the guardband can be set to minimize four-wave mixing (FWM) .
  • a guardband centered upon the ⁇ 0 has a width such that the absolute value of dispersion values in both the high and low subbands is approximately equal to or greater than 0.5 ps/nm-km.
  • a guardband of about 17 nm centered upon the ⁇ 0 is used to separate the high and low subbands .
  • the width of the guardband avoids four-wave mixing FWM by assuring that closely spaced carriers co-propagate in a dispersive environment, thereby "washing out" the phase coherence required for effective mixing over a length of fiber.
  • a dense concentration of modulated carriers may occupy the low subband and/or high subband without causing any significant interference.
  • the presence of the guardband is especially important in reducing FWM over non- dispersion shifted fiber where the magnitude of dispersion is not as great as in dispersion- shifted fiber.
  • the two subbands or windows can also experience different dispersion values.
  • the low subband or shorter wavelength window experiences negative dispersion and the high subband or longer wavelength window experiences positive dispersion.
  • Positive dispersion in the high subband may be readily compensated using conventional DSF, or the recently introduced LS fiber, because these are optimized for 1550nm and have a substantial negative dispersion in the 1310nm band.
  • Positive dispersion in the high subband can also be corrected or ameliorated by a chirped fiber Bragg grating set to impart a negative dispersion, as is well known in the art.
  • the negative dispersion in the low subband or shorter wavelength window can be compensated by a chirped fiber Bragg grating set to impart a positive dispersion.
  • both the low subband and the high subband experience negative dispersion. Accordingly, such negative dispersion in the low and high subbands can be compensated by a chirped fiber Bragg grating set
  • Single-mode fiber also introduces a positive slope dispersion across the 1310nm window in both the low and high subbands.
  • Such a positive dispersion slope can be corrected or ameliorated by a chirped fiber Bragg grating, as is well known in the art.
  • the 1310nm band is relatively wide, bracketed on the . long end by the absorption peaks of silica and water. There is also a minimum wavelength limit imposed by the geometry of the fiber to guarantee single-mode propagation.
  • the present invention provides low and high subbands spanning approximately 1270-1300nm and 1320-1365nm, allowing for considerably more channels than are expected with the popular, but narrow erbium band.
  • a multi -channel optical communication system and method involves a plurality of carrier signals transported through a single mode fiber.
  • the single mode fiber has a zero dispersion wavelength ⁇ 0 .
  • the carrier signals have wavelengths in at least one of a low subband and a high subband withing a 1310nm band.
  • the low subband and high subband are separated by a guardband that includes the zero dispersion wavelength ⁇ 0 of the single mode fiber.
  • the zero dispersion wavelength ⁇ 0 is in a range between approximately 1309 ⁇ m to 1315nm.
  • the guardband has a width of at least two nm, and preferably, a width of approximately 17nm.
  • the guardband has a range between approximately 1300nm and 1320nm.
  • the low subband has a range between approximately 1270nm and 1300nm, and the high subband has a range between approximately 1320 and 1365nm.
  • -6- carrier signals transport data in respective dense WDM channels within the low subband and the high subband.
  • the dense WDM channels are separated by a channel spacing of at least approximately 100 GHz.
  • the guardband has a range between approximately 1300nm and 1320
  • the low subband has a range between approximately 1295nm and 1300nm
  • the high subband has a range between approximately 1320 and 1365nm.
  • Carrier signals are transported in any one of approximately nine dense WDM channels within the low subband and approximately seventy- six dense WDM channels within the high subband. Each of these dense WDM channels within the low and high subbands is separated by a channel spacing of at least approximately 100 Ghz .
  • a method and system for dense WDM dispersion compensation is provided.
  • a dense WDM DCM unit compensates for negative dispersion and/or positive dispersion in the plurality of carrier signals transported over a single mode fiber in the respective dense WDM channels.
  • the dense WDM dispersion compensation unit has a positive dispersion compensation unit (DCM) and a negative dispersion compensation unit (DCM) .
  • the positive DCM compensates for positive dispersion in each carrier signal transported over NDSF in the respective dense WDM channels in the high subband.
  • the positive DCM can be a dispersion shifted fiber segment and/or a chirped fiber Bragg grating designed to impart a negative dispersion value having sufficient magnitude to correct or ameliorate the magnitude of the positive dispersion of NDSF. In this way, the dispersion shifted fiber segment and/or the chirped fiber Bragg grating
  • negative DCM compensates for negative dispersion in each carrier signal transported over NDSF in the respective dense WDM channels in the low subband.
  • negative DCM can be a chirped fiber Bragg grating to compensate for the magnitude of negative dispersion in each carrier signal transported over NDSF in respective dense WDM channels in the low subband.
  • the dense WDM DCM need only be a negative DCM which compensates for negative dispersion in each carrier signal in the respective dense WDM channels in the low subband and high subbands.
  • a negative DCM can be a chirped fiber Bragg grating that imparts a positive dispersion value which compensates for the magnitude of negative dispersion in each carrier signal transported over DSF in respective dense WDM channels in the low and high subbands .
  • a dense WDM DCM can also compensate for the positive- slope dispersion imparted by single mode fiber.
  • a chirped fiber Bragg grating can be used to finely compensate for the slope of positive dispersion in each carrier signal transported over a single mode fiber (NDSF or DSF) in respective dense WDM channels in the low and high subbands .
  • a wavelength division multiplexing unit is optically coupled to a single mode fiber. The WDM unit multiplexes individual carrier signals and outputs the plurality of carrier signals to the single mode fiber.
  • the wavelength division multiplexing unit can comprise at least one
  • FIG. 1 is a diagram showing dense wavelength division multiplexing (WDM) in the 1310 nm window according to one embodiment of the present invention.
  • WDM dense wavelength division multiplexing
  • FIG. 2A is a diagram showing an example of 85 channels at 100 GHz spacing in the dense WDM 1310nm window of FIG.l
  • FIG. 2B is a table showing an example of 100 channels at 100 GHz spacing including 85 channels in high and low subbands and 15 channels in a guardband, as shown in FIG. 2A.
  • FIG. 3A is a diagram that shows dispersion for NDSF and DSF single-mode fibers in a 1310nm window.
  • FIG. 3B is a diagram that shows dispersion for an NDSF single-mode fiber in 80 channels of a 1310nm window.
  • FIG. 3C is a diagram that shows dispersion for a DSF single-mode fiber in 80 channels of a 1310nm window.
  • FIG. 3D is a diagram that shows dispersion for a DSF TRUEWAVETM single-mode fiber in 80 channels of a 1310nm window.
  • FIG. 3E is a diagram that shows dispersion for a DSF linearly- sloped (LS) single-mode fiber in 80 channels of a 1310nm window.
  • FIG. 4 is a diagram of an example fiber link segment supporting WDM in the 1310nm window according to the present invention.
  • FIG. 5 is a diagram of another example fiber link segment supporting WDM in the 1310nm window according to the present invention.
  • FIG. 6 is a diagram showing in more detail an example of the dense WDM dispersion compensation module of FIGs. 4 and 5.
  • FIG. 7 is a graph illustrating the dispersion limited distance in approximately typical and best cases of OC-48 optical communication carried over a NDSF single-mode fiber.
  • FIG. 8 is a graph illustrating the loss limited distance in approximately typical and best cases of OC-48 and OC-192 optical communication carried over a NDSF single-mode fiber.
  • 1310nm band refers to a band of wavelengths within a range of approximately 1150 nanometer (nm) and 1385nm.
  • FIG. 1 is a diagram showing dense wavelength division multiplexing (WDM) in the 1310nm window 100
  • an optical communication link (not shown in FIG. 1) carries dense WDM optical signals within 1310nm window 100 instead of, or in addition to, the erbium band.
  • the optical communication link has at least one single-mode fiber, including, but not limited to, non-dispersion shifted fiber (NDSF) and dispersion shifted fiber (DSF) .
  • DSF can include linearly- sloped dispersion shifted fiber (LSF) .
  • Example fiber links supporting a dense DWM according to the present invention are described in further detail with respect to FIGs. 4-5.
  • guardband 120 includes the zero dispersion wavelength ⁇ 0 of a single-mode fiber in the optical communication link and separates low subband 140 and high subband 160.
  • zero dispersion wavelength ⁇ 0 is 1312nm ⁇ 3nm as found in many installed or new single mode fibers in a fiber optic network.
  • Guardband 120 is approximately 17nm wide and centered upon ⁇ 0 .
  • guardband 120 covers a range of wavelengths between approximately 1303nm and 1320nm to separate low subband 140 and high subband 160.
  • Low subband 140 covers a wavelength range between approximately 1270nm and 1303nm.
  • High subband 160 covers a range between approximately 1320nm and 1365nm.
  • one or more channels having equal or non-equal spacing can be provided in low subband 140 and/or high subband 160. Channels are not provided in guardband 120. Further, the width of guardband 120 can be provided.
  • a guardband centered upon the ⁇ 0 has a width such that the absolute value of dispersion values in both the high and low subbands is approximately equal to or greater than 0.5 ps/nm-km.
  • a guardband of about 17nm centered upon the ⁇ 0 is used to separate the high and low subbands. This avoids four-wave mixing by assuring that closely space carriers co-propagate in a dispersive environment, thereby "washing out" the phase coherence required for effective mixing over a length of fiber. Therefore, a dense concentration of modulated carriers may occupy each subband 140, 160 without causing any significant interference.
  • the wavelength values shown in FIG. 1 are illustrative and can be varied.
  • the 1310nm band is relatively wide, bracketed on the long end by the absorption peak of water (approximately 1385nm) .
  • Guardband 120 and subbands 140 and 160 can also vary in size depending upon a particular application as would be apparent to one skilled in the art given this description.
  • This dense WDM multi -channel plan according to the present invention allows for considerably more channels than are expected with the popular, but narrower, erbium band.
  • Optical transducers and amplifiers for operation in the 1310nm band are also relatively inexpensive.
  • FIG. 2A is a diagram
  • FIG. 2B is a table showing an example of 100 channels at 100 GHz spacing including the 85 channels in high and low subbands and 15 channels (not used) in a guardband shown in FIG. 2A. Each channel is listed with a nominal frequency (f) in Terahertz (THz) and center wavelength ⁇ (nm) .
  • f nominal frequency
  • THz Terahertz
  • ⁇ center wavelength
  • low subband 140 includes 9 channels at 100 GHz spacing between approximately 1295nm and 1300nm.
  • High subband 160 includes 76 channels at 100 GHz spacing between approximately 1320nm and 1365nm.
  • more channels can certainly be added in low subband 140 or high subband 160.
  • channels at wavelengths below 1295nm can be added.
  • Channels at wavelengths above 1365nm or within guardband 120 can be used as well depending upon a particular design application and tolerance.
  • Channel spacing can also be smaller than 100 GHz to add even more channels, especially for low bit rates.
  • Channel spacing greater than 100 GHz (or even greater than 200 GHz) can be provided to further ensure signal separation.
  • a 100 GHz spacing requirement translates to a wavelength range of approximately 0.8nm. This means only 40 WDM channels fit within the erbium fiber band. If each optical carrier is modulated at high data bit rates, such as 10 Giga-bits/second (Gb/s) , a 200 GHz spacing is used between channels to avoid crosstalk. As a result, only sixteen channels with 200 GHz spacing can be used effectively in an operating window within an erbium band of approximately 1530 to 1561nm. Thus, even the conservative dense WDM design of FIGs. 2A and 2B
  • carriers in subbands 140 and 160 also experience different dispersion values. As shown in FIGS.3A-3E, carriers in low subband 140 and high subband 160 within a 1310nm window experience either positive or negative dispersion along a single-mode fiber depending the fiber type. Single mode fiber (NDSF and DSF) also introduces a positive slope dispersion across the 1310nm window.
  • NDSF and DSF Single mode fiber
  • FIG. 3A is a diagram that shows dispersion for NDSF and DSF single-mode fibers in a 1310nm window.
  • the NDSF fiber is a CORNING® SMF-28 fiber having a dispersion value between approximately -6.0 and 6.0 within a 1310nm window (approx. 1270nm to 1374nm) .
  • FIG. 3B is a diagram that shows a dispersion range between approx. -1.595 to 5.329 for an NDSF single-mode fiber (SMF-28) in 80 channels of a 1310nm window between approx. 1295nm. and 1374nm.
  • SMF-28 NDSF single-mode fiber
  • DSF single-mode fiber including TRUEWAVETM and linearly- sloped (LS) fiber
  • LS linearly- sloped
  • FIG. 3C is a diagram that shows dispersion for a DSF single-mode fiber in 80 channels of a 1310nm window.
  • the dispersion value is between approximately -24.653 and -15.425 within a 1310nm window (approx. 1295nm to 1374nm) .
  • FIG. 3D is a diagram that shows dispersion for a DSF TRUEWAVETM single-mode fiber in 80 channels of a 1310nm window.
  • the dispersion value is between approximately -21.201 and - 12.317 within a 1310nm window (approx. 1295nm to 1374nm) .
  • FIG. 3E is a diagram that shows dispersion for a DSF linearly- sloped (LS) single-mode fiber in 80 channels of a 1310nm window.
  • the dispersion value is between approximately -27.841 and -17.876 within a 1310nm window (approx. 1295nm to 1374nm) .
  • Carriers in low subband 140 experience negative dispersion along NDSF.
  • Carriers in high subband 160 experience positive dispersion along NDSF.
  • the latter (positive dispersion) may be readily compensated using one or more segments of conventional DSF, or the recently introduced LS fiber, because these are optimized for 1550nm and have a substantial negative dispersion at 1310nm.
  • Positive dispersion across high subband 160 can also be corrected or ameliorated by one or more chirped fiber Bragg gratings, as is well known in the art.
  • the negative dispersion in low subband 140 (and/or in high subband 160) can be compensated by one or more chirped fiber Bragg gratings. Such dispersion compensation is described in further detail below with respect to FIG. 6.
  • dense WDM in the 1310nm band will now be described with respect to example fiber link segments in FIGs. 4 and 5.
  • An example dense WDM dispersion compensation module (DCM) is also described with respect to FIG. 6.
  • FIG. 4 is a diagram of an example fiber link segment 400 supporting WDM in the 1310nm window according to the present invention.
  • Fiber link 400 includes a narrow wavelength division multiplexer (WDM) 410, a single mode fiber 415, a bi-directional optical amplifier 420, and a dense WDM dispersion compensation module (DCM) 440.
  • WDM 410 can be any type of wavelength division multiplexer and/or demultiplexer or combinations of wavelength division multiplexer/demultiplexers.
  • Single mode fiber 415 can be any type of single mode fiber including, but not limited to, NDSF (CORNING®SMF-28) and DSF fibers (DS, TRUEWAVETM and LS) .
  • Bi-directional optical amplifier 420 can be any type of bi-directional optical amplifier for amplifying 1310nm band wavelengths. Dense WDM DCM 440 is described further with respect to FIG. 6. Other optical components such as couplers, splitters, etc. can be used is well-known in WDM communications. Optical emitters and receivers (not shown) are also provided to generate and detect the carrier signals in the respective dense WDM channels, that is, the low subband and the high subband channels.
  • fiber link segment 400 is bi-directional carrying traffic in two directions along the same fiber.
  • these directions can be East and West between two cities.
  • WDM 410 receives carriers for dense WDM channels traveling in one direction (i.e. West) and multiplexes them onto single mode fiber 415.
  • WDM 410 receives carriers for dense WDM channels traveling in the other direction (i.e. East) and demultiplexes them from single mode fiber 415.
  • any combination of the dense WDM channels in the 1310nm can be allocated for carrying
  • Fiber link 400 can also be modified to be two uni- directional links.
  • FIG. 5 is diagram of another example of fiber link segment 400 supporting WDM in the 1310nm window according to the present invention.
  • WDM 410 is replaced by four narrow WDMs 504, 505, 506, and 507 and a WDM 503 which can be a narrow, coarse, or broadband WDM.
  • WDM 504 to minimize the potential of crosstalk or other interference, four carriers in four respective low subband channels traveling in one direction (West) are received at WDM 504 for multiplexing and transmission to WDM 503.
  • WDM 506 for multiplexing and transmission to WDM 503.
  • WDM 503 then multiplexes the eight low subband channels for transmission over single mode fiber 415.
  • WDM 503 demultiplexes eight high subband channels received from single mode fiber 415 into two groups of four high subband channels.
  • One group of four respective high subband channels traveling in one direction (East) are then received at WDM 505 for further demultiplexing and transmission to optical receivers.
  • the other group of four carriers in four respective high subband channels traveling in one direction (East) are received at WDM 507 for demultiplexing and transmission to optical receivers .
  • FIG. 5 shows 16 channels in groups of four for illustrative purposes. The present intention is not so limited, as any number of channels can be allocated between WDMs 504-507 in dense WDM within the 1310nm window in the low subband 140 and/or high subband 160 as discussed above. Further to minimize cross -talk and interference even more, different groups of channels within low subband 140 can be allocated to travel in different directions (likewise, different groups of channels within high subband 160 can be allocated to travel in different directions) .
  • FIG. 6 is a diagram showing in more detail an example dense WDM dispersion compensation module (DCM) 440 for use with NDSF fiber.
  • Dense WDM DCM 440 includes two wavelength splitter/combiners 620 and 640. Negative dispersion compensation unit 660 (negative DCM 660) and positive dispersion compensation unit 680 (positive DCM 680) are provided in parallel between wavelength splitter/combiners 620 and 640. Dense WDM DCM 440 is especially important for dispersive fiber media and long distance fiber links.
  • positive DCM 680 compensates for the positive dispersion (in magnitude and/or slope) along NDSF.
  • positive DCM 680 can include one or more
  • Positive DCM 680 can also include a chirped fiber Bragg grating to compensate for positive dispersion, as is well known in the art. See, e.g., Agrawal, "Fiber- Optic Communica tion Sys tems, " Second Ed. (John Wiley & Sons: New York 1997), section 9.6.2, chapter 9, pp. 425-466. Carriers in low subband 140 experience negative dispersion along NDSF, and thus are passed by wavelength combiners/splitters 620, 640 to negative DCM 660. Negative DCM 660 compensates for the negative dispersion along NDSF. For example, negative DCM 660 can be a chirped fiber Bragg grating set to compensate for negative dispersion, as is well known in the art.
  • negative dispersion can occur in both the low subband 140 and the high subband 160 when single mode fiber 415 is a DSF fiber (DS, TRUEWAVETM or LS) .
  • dense WDM DCM 440 need only include negative DCM 660. All channels in low subband 140 and high subband 160 are then compensated for the negative dispersion by negative DCM 660.
  • carriers in the dense WDM channels in the low and high subbands pass through one or more chirped fiber Bragg gratings to compensate for the negative dispersion along DSF.
  • dense WDM DCM 440 can also compensate for the positive- slope dispersion imparted by single mode fiber.
  • chirped fiber Bragg grating (s) can be used to finely compensate for the slope of positive dispersion in each carrier signal transported over a single mode fiber (NDSF or DSF) in respective dense WDM
  • a high-speed fiber optic network or link using a dense WDM in the 1310nm window according to the present invention can include, but is not limited to, an OC-48 or OC-192 bit rate.
  • a fiber type SMF-28, SMF-DS, SMF-LS, and TRUEWAVETM can be used.
  • FIG. 7 is a graph illustrating examples of the dispersion limited distance in typical and best cases of OC-48 optical communication carried over a DSF single-mode fiber.
  • the distance an OC-48 carrier signal can travel is limited to- about 1750 km for a low dispersion value of -10 ps/nm-km and to about 198km for a higher dispersion value of -30 ps/nm-km.
  • the distance an OC-48 carrier signal can travel is limited to about 2900 km for a low dispersion value of -10 ps/nm-km and to about 300 km for a higher dispersion value of -30 ps/nm-km.
  • FIG. 8 is a graph illustrating examples of the loss in transmitted power over distance.
  • the distance an OC-48 carrier signal can travel and be satisfactorily detected can be limited by the transmitter power.
  • the distance varies between about 60 and 100 km for OC-48 signals transmitted by transmitters having a transmitter power between 1 and 21 dBm.
  • the plot in FIG. 8 assumes a minimum receiver level during normal operation of about
  • the unit “dB" is a derived unit for expressing
  • FIGs. 7 and 8 are not intended to limit the scope of the present invention.
  • different link and network designs and components e.g. higher transmitter powers, low dispersion fibers, frequent spacing of optical amplifiers or regenerators, and a different dispersion compensation module (DCM) can be used to achieve long-distance fiber optic communication using dense WDM in the 1310nm band according to the invention.
  • DCM dispersion compensation module

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Abstract

On effectue un multiplexage par répartition en longueur d'onde dense dans une bande 1310nm le long d'une fibre monomode. Les longueurs d'ondes porteuses sont sélectionnées dans deux fenêtres, une sous-bande basse (140) et/ou une sous-bande haute (160), de part et d'autre de la bande de garde (120). Cette bande de garde comprend la longueur d'onde de dispersion nulle d'une fibre monomode dans la liaison de communication optique, et sépare la sous-bande basse et la sous-bande haute dans la bande 1310nm. On corrige la dispersion des signaux porteurs dans chaque voie MRL dense dans les sous-bandes basse et haute.
PCT/US1999/003573 1998-02-20 1999-02-19 Mrl dense dans la bande 1310nm WO1999043118A1 (fr)

Priority Applications (4)

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JP2000532943A JP2002504777A (ja) 1998-02-20 1999-02-19 １３１０ｎｍ帯域における高密度波長分割多重方法およびシステム
MXPA00008183A MXPA00008183A (es) 1998-02-20 1999-02-19 Wdm densa en la banda de 131onm.
CA002321500A CA2321500A1 (fr) 1998-02-20 1999-02-19 Mrl dense dans la bande 1310nm
EP99913813A EP1053614A4 (fr) 1998-02-20 1999-02-19 Mrl dense dans la bande 1310nm

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US7540498P 1998-02-20 1998-02-20
US60/075,404 1998-02-20
US09/106,725 US6043914A (en) 1998-06-29 1998-06-29 Dense WDM in the 1310 nm band
US09/106,725 1998-06-29

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WO1999043118A1 true WO1999043118A1 (fr) 1999-08-26

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EP (1) EP1053614A4 (fr)
JP (1) JP2002504777A (fr)
CA (1) CA2321500A1 (fr)
MX (1) MXPA00008183A (fr)
WO (1) WO1999043118A1 (fr)

Cited By (8)

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Publication number Priority date Publication date Assignee Title
EP1098212A1 (fr) * 1999-11-05 2001-05-09 JDS Uniphase Inc. Compensateur de dispersion accordable
EP1104957A1 (fr) * 1999-06-15 2001-06-06 Mitsubishi Denki Kabushiki Kaisha Dispositif et systeme de compensation de dispersion
US6353497B1 (en) 2000-03-03 2002-03-05 Optical Coating Laboratory, Inc. Integrated modular optical amplifier
US6654564B1 (en) 1999-11-05 2003-11-25 Jds Uniphase Inc. Tunable dispersion compensator
US6885824B1 (en) 2000-03-03 2005-04-26 Optical Coating Laboratory, Inc. Expandable optical array
EP1109341A3 (fr) * 1999-12-16 2005-09-28 Lucent Technologies Inc. Multiplexeur d'insertion/extraction de longueur d'onde optique pour débits de transmission à signaux duaux
EP1722495A1 (fr) * 2005-05-11 2006-11-15 Alcatel Procédé de transmission d'un signal optique dans un système de transmission optique, et système de transmission optique correspondant
WO2007149213A3 (fr) * 2006-06-02 2008-07-17 Aurora Networks Inc Transport dwdm de signaux de télévision par câble et de signaux numériques par fibre optique dans des régions spectrales de faible

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US5696614A (en) * 1993-08-10 1997-12-09 Fujitsu Limited Optical wavelength multiplex transmission method and optical dispersion compensation method

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US5321541A (en) * 1991-12-12 1994-06-14 At&T Bell Laboratories Passive optical communication network with broadband upgrade

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US5343322A (en) * 1991-12-31 1994-08-30 France Telecom System of very-long-distance digital transmission by optical fiber with compensation for distortions at reception
US5696614A (en) * 1993-08-10 1997-12-09 Fujitsu Limited Optical wavelength multiplex transmission method and optical dispersion compensation method

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Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1104957A1 (fr) * 1999-06-15 2001-06-06 Mitsubishi Denki Kabushiki Kaisha Dispositif et systeme de compensation de dispersion
EP1104957A4 (fr) * 1999-06-15 2006-06-14 Mitsubishi Electric Corp Dispositif et systeme de compensation de dispersion
EP1098212A1 (fr) * 1999-11-05 2001-05-09 JDS Uniphase Inc. Compensateur de dispersion accordable
US6654564B1 (en) 1999-11-05 2003-11-25 Jds Uniphase Inc. Tunable dispersion compensator
EP1109341A3 (fr) * 1999-12-16 2005-09-28 Lucent Technologies Inc. Multiplexeur d'insertion/extraction de longueur d'onde optique pour débits de transmission à signaux duaux
US6353497B1 (en) 2000-03-03 2002-03-05 Optical Coating Laboratory, Inc. Integrated modular optical amplifier
US6885824B1 (en) 2000-03-03 2005-04-26 Optical Coating Laboratory, Inc. Expandable optical array
EP1722495A1 (fr) * 2005-05-11 2006-11-15 Alcatel Procédé de transmission d'un signal optique dans un système de transmission optique, et système de transmission optique correspondant
US7881610B2 (en) 2005-05-11 2011-02-01 Alcatel Method of transmitting an optical signal in an optical transmission system and optical transmission system for implementing such a method
WO2007149213A3 (fr) * 2006-06-02 2008-07-17 Aurora Networks Inc Transport dwdm de signaux de télévision par câble et de signaux numériques par fibre optique dans des régions spectrales de faible

Also Published As

Publication number Publication date
JP2002504777A (ja) 2002-02-12
EP1053614A1 (fr) 2000-11-22
EP1053614A4 (fr) 2002-10-23
CA2321500A1 (fr) 1999-08-26
MXPA00008183A (es) 2002-06-04

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