Single-mode optical fiber optimized for operation in 0 and e bands, and corresponding optical transmission system

The optimized monomod optical fiber addresses high chromatic dispersion in O and E bands by adjusting refractive index profiles, enabling efficient operation and doubling wavelength channels in MWDM systems while maintaining compatibility with G.652 and G.657 standards.

FR3154513A1Active Publication Date: 2025-04-25DRAKA COMTEQ FRANCE SAS
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Patent Information

Application Number
FR2023011265
Authority / Receiving Office
FR · FR
Patent Type
Applications
Current Assignee / Owner
Filing Date
2023-10-18
Publication Date
2025-04-25
Estimated Expiration
2043-10-18

AI Technical Summary

Technical Problem

Existing monomod optical fibers struggle to operate efficiently in the O and E wavelength bands due to high chromatic dispersion, limiting their use in advanced multiplexing systems like MWDM, while adhering to ITU-T G.652 and G.657 recommendations.

Method used

A monomod optical fiber design with specific refractive index profiles and coating layers, including a soul with varying refractive indices and a coating comprising multiple layers, optimized to achieve a zero dispersion wavelength between 1340 and 1360 nm, enabling operation in the O and E bands with reduced chromatic dispersion.

Benefits of technology

The optimized optical fiber maintains similar performance to G.652 and G.657 fibers but operates effectively in higher wavelengths, supporting MWDM systems with reduced dispersion penalties, doubling wavelength channels and enhancing compatibility with existing CWDM technology.

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Abstract

The invention relates to a single-mode optical fiber comprising: a core (10) having a refractive index n, in which the core includes a region in which the value of n decreases from a value n0 to a value n2; and a coating (20) comprising: a first coating layer (21) in which the refractive index is n2; and a second coating layer (22) in which the refractive index is n3, less than n2; a third coating layer (23) in which the refractive index is n4 greater than n3; in which the core radius r1 is between 2.5 µm and 5.5 µm; and in which a refractive index difference ∆n0 = n0-n4 is greater than 5.8 × 10-3; and in which the difference in refractive index ∆n2 = n2 - n4 is between 1 × 10⁻³ and 2.5 × 10⁻³; and in which the difference in refractive index ∆n3 = n3 - n4 is less than 0. Figure for the abbreviation: Figure 2
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Description

Title of the invention: Single-mode optical fiber optimized for operation in o and e bands, and corresponding optical transmission system technical field

[0001] This disclosure relates to single-mode optical fibers used in optical transmission systems, and to optical transmission systems comprising such single-mode fibers. More specifically, the present invention relates to single-mode optical fibers that are optimized to operate in the O and E wavelength bands. State of the art

[0002] Telecommunications systems require optical fibers capable of transmitting signals over long distances without degradation. Such optical fiber transmission systems often use single-mode fibers (SMF), for example, so-called "standard" single-mode fibers (SSMF), which are used in terrestrial transmission systems. Indeed, a single-mode fiber (SMF) provides lower optical signal attenuation compared to a multi-mode fiber (MMF), and is therefore better suited to long-distance transmissions. Furthermore, as its name suggests, a multi-mode fiber has multiple modes, each with different speeds, resulting in limited bandwidth, unlike a single-mode fiber which theoretically has unlimited bandwidth, making it more suitable for long-distance transmissions.

[0003] Furthermore, to facilitate compatibility between optical systems from different manufacturers, the International Telecommunication Union (ITU) has defined several standards with which a standard optical transmission fiber must conform. Among these standards, ITU-T Recommendation G.652 (latest revision of November 2016) describes the characteristics of cable-based and single-mode fiber networks that can meet the growing demand for broadband services. ITU-T Recommendation G.652 (hereinafter referred to as "G.652") contains several attributes (i.e., A, B, C, and D) defining the fiber attributes of a single-mode optical fiber. ITU-T Recommendation G.657 (hereinafter referred to as "G.657") focuses more specifically on bend-loss-insensitive single-mode fibers. In particular, the attributes of G.657.Al and G.657.A2 (Last revision November 2016) are presented below.

[0004] The different communication bands of optical wavelengths can be used to transmit information through an optical fiber. These bands correspond to a wavelength region in which optical fibers have lower transmission losses. This low-loss wavelength region extends from 1260 nm to 1625 nm and is divided into five wavelength bands called O, E, S, C, and L bands.

[0005] Currently, most single-mode optical fibers operate at wavelengths generally ranging from 1260 nm to 1625 nm, and more particularly in the O band (1260-1360 nm) and the C&L bands (1530-1625 nm), which is the case for G.652 and G.657 optical fibers.

[0006] More specifically, the optical performance of category A of recommendation G.657 is: a mode field diameter (MFD) for a wavelength of 1310 nm between 8.6 and 9.2 pm, a cable cut-off of less than 1260 nm, and a zero dispersion wavelength (ZDW) between 1300 and 1324 nm (such a ZDW is optimal for use with O-band fibers), and a zero dispersion slope (ZDS) less than or equal to 0.092 ps / (nm2-km).

[0007] The maximum acceptable macro-bend losses of G.657 fibers are:

[0008] [Table 1] G.657.A1 G.657.A2 10 turns at a radius of 15 mm, measured at 1550 nm (R15BL at 1550) 0.25 dB 0.03 dB 10 turns at a radius of 15 mm, measured at 1625 nm (R15BL at 1625) 1.0 dB 0.1 dB 1 turn at a radius of 10 mm, measured at 1550 nm (R15BL at 1550) 0.75 dB 0.1 dB 1 turn at a radius of 10 mm, measured at 1625 nm (R15BL at 1625) 1.0 dB 0.2 dB 1 turn at a radius of 7.5 mm, measured at 1550 nm (R15BL at 1550) 0.5 dB 1 turn at a radius of 7.5 mm, measured at 1625 nm (R15BL at 1625) 1.0 dB

[0009] International applications WO2015 / 092464 and WO2019 / 122943 disclose examples of optical fibers having a zero dispersion wavelength between 1300 and 1324 nm according to standards G.652 and G.657A.

[0010] However, with the long-term trend towards an increasing expansion of capacities As data traffic continues to grow rapidly, it becomes necessary to optimize the use of wavelengths at the top of the O-band used for fiber optic communications because chromatic dispersion will be too high at these wavelengths for existing equipment. Specifically, Medium Wavelength Division Multiplexing (MWDM) systems with 25G transceivers, for example, should operate in the O and E bands, from 1268 to 1375 nm, and require chromatic dispersion ranging from -9.5 to +3 ps / nm²-km. This is not achieved with current G.652 and G.657.A fibers, as the zero-dispersion wavelength ranges from 1300 to 1324 nm. Therefore, there is a need to find a fiber optic design capable of meeting this requirement. Presentation of the invention

[0011] These objectives are achieved by the invention, which relates to a single-mode optical fiber comprising: - a core having a refractive index n, the core comprising a region in which the value of n decreases from a value n0 at a radius r0 to a value n2 at a radius ri; and - a coating having a refractive index n', said coating comprising: • a first coating layer in which the refractive index n' is equal to n2; and • a second coating layer in which the refractive index is equal to a value n3 less than n2; • a third coating layer in which the refractive index is equal to a value n4 greater than n3;

[0012] in which the core radius ri is between 2.5 pm and 5.5 pm; and

[0013] in which a difference in refractive index An0 = n0-n4 is greater than 5.8x10 3; and

[0014] in which a difference in refractive index An2 = n2-n4 is between 1x103 and 2.5x103; and

[0015] in which a difference in refractive index An3 = n3-n4 is less than 0.

[0016] Thus, this invention makes it possible to obtain optical fibers operating optimally in the O and E wavelength bands, therefore with a Chromatic Dispersion (CD) slightly shifted compared to G.652 and G.657 fibers but exhibiting the same optical performance. More particularly, the optical fiber according to the invention exhibits the same properties as G.657.A fibers: an MFD-1310 at 9.0 pm, a cable cutoff of less than 1260 nm, and low bend losses; with the exception of the ZDW, which is between 1340 and 1360 nm. Thus, the optical fiber according to the invention makes it possible to maintain the chromatic dispersion between -9 and +3 ps / nm-km in the range from 1268 to 1375 nm.

[0017] Therefore, the invention is ideal for use in medium-wavelength division multiplexing (MWDM) systems. These systems allow the number of wavelength channels to be doubled under the same conditions as in commonly used coarse-wavelength division multiplexing (CWDM) systems, by reducing the wavelength spacing of CWDM from 20 nm to 10 nm.

[0018] Ultimately, medium wavelength division multiplexing (MWDM) is proposed to meet the urgent needs of 5G commercialization. And since it only makes parameter adjustments based on mature CWDM technology, the industry can reuse the CWDM module production process and the industrial chain can quickly respond to market demand.

[0019] According to a particular embodiment, the third coating layer is composed of silica.

[0020] According to another embodiment, the refractive index profile of the core and the coating is defined by the following profile parameters:

[0021] = Seen - 5.85 x VOi

[0022] K2 = V02 + 0.65 x VOi

[0023] K3 = V03 - 5 x K2

[0024] where

[0025] Voi (pin) is a surface integral of the soul;

[0026] Vu (pm2) is a volume integral of the soul;

[0027] V02 (pm) is a surface integral of the first coating layer;

[0028] Vos (pm) is a surface integral of the second coating layer;

[0029] and in which said parameters respect the following inequalities:

[0030] -59 < Ki < -47

[0031] 18 <K2<24

[0032] -133 <K3<-118

[0033] According to a particular aspect of the invention, the profile of the refractive index or of the core is trapezoidal, with a ratio between 0 and 1, and preferably between 0.05 and 0.95, in which said ratio is equal to r^i.

[0034] According to another particular aspect of the invention, the profile of the refractive index or of the core has rounded edges.

[0035] According to a particular embodiment, the refractive index profile of the core has a depressed internal central zone, extending from the center of the core to the radius rD, in which rD is less than rb and in which the refractive index n of the core has a minimum value at the center of the core equal to n0D, in which n0D is in- less than n0.

[0036] According to a particular aspect of the invention, the region exhibiting a decrease in refractive index is obtained by progressively changing the concentration of at least two dopants.

[0037] According to one embodiment of the invention, the at least two dopants are chosen from the following elements and / or molecules: - germanium oxide (GeO2); - fluorine (F); - phosphorus oxide (PXOY); - boron oxide (BXOY); - aluminum oxide (Al2O3).

[0038] According to a particular aspect of the invention, said optical fiber exhibits a chromatic dispersion between -9 and +3 ps / nm-km in the wavelength range from 1268 to 1375 nm.

[0039] Consequently, the chromatic dispersion is slightly shifted with respect to G.562 and G.567 optical fibers, which allows operation in both the O and E wavelength bands.

[0040] According to one embodiment of the invention, said optical fiber has a mode field diameter (MFD) at a wavelength of 1310 nm which is between 8.6 and 9.2 pm and preferably equal to 9 pm.

[0041] According to a particular aspect of the invention, said optical fiber has a cable cutoff wavelength between 1170 nm and 1260 nm.

[0042] According to a particular aspect of the invention, the optical fiber has a zero dispersion wavelength between 1340 and 1360 nm.

[0043] The invention also relates to an optical fiber transmission system comprising at least one single-mode optical fiber as described above.

[0044] Consequently, the range of wavelengths that can be used by this system is wider than those available for the prior art optical communication system. Indeed, it can operate in the O and E wavelength bands (from 1268 to 1375 nm) using, for example, medium wavelength division multiplexing (MWDM) with a 25 Gb / s transceiver.

[0045] According to one embodiment of the invention, the optical fiber transmission system has a maximum emitter dispersion penalty of 1.5 dB. Figures

[0046] This disclosure can be better understood with reference to the following description and drawings, given by way of example and not limiting the scope of protection, in which:

[0047] [Fig.1] represents an optical fiber according to the invention;

[0048] [Fig.2] is a schematic representation of the evolution of the refractive index (a) of the core and coating of an optical fiber according to [Fig.1], according to a first example of invention, as well as a cross-sectional view (b) of such an optical fiber;

[0049] [Fig.3] is a schematic representation of the evolution of the refractive index of the core and coating of an optical fiber according to [Fig.3], according to a second example of the invention, the refractive index profile of the core comprising rounded edges;

[0050] [Fig.4] is a schematic representation of the evolution of the refractive index of the core and coating of an optical fiber according to [Fig.3], according to a third example of the invention, the refractive index profile of the core comprising a depressed central area;

[0051] [Fig.5] is a schematic representation of the evolution of the refractive index of the core and coating of an optical fiber according to [Fig.3], according to a fourth example of the invention, the refractive index profile of the core comprising a depressed central area and rounded edges;

[0052] [Fig.6] is a schematic representation of a transmission system comprising an optical fiber according to the invention.

[0053] The components shown in the figures are not necessarily to scale; rather, the emphasis is on illustrating the principles of the invention. Description of the implementation methods

[0054] The general principle of the invention is based on a single-mode optical fiber configured for use in optical transmission systems operating in a wavelength range between 1260 nm and 1625 nm. More particularly, the invention is based on a single-mode optical fiber optimized for use in the higher wavelengths of the O-band and even in the E-band (for example, around 1375 nm). Indeed, the specific characteristics of the single-mode optical fiber according to the invention make it possible to obtain a chromatic dispersion (CD) slightly shifted compared to G.652 and G.657 fibers, but with the same optical performance. More particularly, the single-mode optical fiber according to the invention has a ZDW between 1340 and 1360 nm, making it possible to maintain the chromatic dispersion (CD) between -9 and +3 ps / nm-km in the range from 1268 to 1375 nm.Such a ZDW and all other optical parameters are obtained through the specific characteristics of the different elements composing the fiber.

[0055] Furthermore, as with G.652 and G.657 fibers, the optical fiber according to the invention has a mode field diameter (MFD) at a wavelength of 1310 nm which is between 8.6 and 9.2 pm and preferably equal to 9 pm. The optical fiber also has a cable cutoff wavelength between 1170 nm and 1260 nm. Thus, this optical fiber has characteristics similar to G.652 and G.657 fibers, but it is further optimized for use in the higher wavelengths of the O-band.

[0056] As illustrated in [Fig. 1], the optical fiber 1 according to the invention comprises a core 10, which is the internal element of the light-carrying fiber, and a coating (or sheath) 20, which serves to confine the light to the core. The coating comprises three coating layers: a first coating layer 21, also called the "intermediate coating," a second coating layer 22, also called the "trench," and a third coating layer 23, also called the "outer coating."

[0057] The core 10 is defined by a radius r and a refractive index n varying with the radius r, while the coating is defined by a radius r' and a refractive index n' varying with the radius r'. More particularly, [Fig. 2] shows the index profile of an optical fiber in the upper part (a) and a cross-sectional view of this optical fiber in the lower part (b) according to the invention. In part (a) of this figure, the evolution of the refractive index (n, n') of the core 10 and the coating 20 as a function of the radius (r, r') from the center of the core 10 is shown.

[0058] According to the invention, the core 10 is defined with an external radius rb. The core 10 comprises a first region extending from its center (r=0) to a radius r0. In the embodiment illustrated in [Fig. 2], the first region of the core has a constant refractive index equal to n0. The optical core 10 further comprises a second region extending from radius r0 to radius rb with a decreasing refractive index, and with a refractive index n2 at radius rb. In the embodiment illustrated in [Fig. 2], the index of the core in the second region decreases from n0 to n2. Furthermore, in the embodiment of [Fig. 2], the radii and indices of the core are defined as follows: • 0.180 pm < r0 < 3 pm • 2.5 pm < ri < 5.5 pm • r0 < r! • An0 > 0.0058, with An0 being the difference in refractive index between the first core region and the third coating layer: An0 = n0 - n4 • IxlO3 < An2 < 2.5x103, with An2 being the difference between the index in ri (in the external part of the second core region) and the index of the third coating layer: An2 = n2 - n4

[0059] More particularly according to a particular embodiment of the invention, An0 is between 0.0058 and 0.0085.

[0060] Furthermore, the radius parameters of the core 10 can be further defined as follows: 0 < r0 < rb, where r is the ratio between the radius of the first region and the second

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[0081] region of the coating being defined as follows: ratio = r0 / rb with 0 < ratio < 1, and preferably, 0.05 < ratio < 0.95. Thus, the core 10 also has an equivalent radius req defined as follows: req = ri x (1 + ratio) / 2, with 1.5 pm < req < 3.5 pm In addition, the refractive index profile of the core 10 can be trapezoidal or rectangular with edges that may or may not be rounded. The index and radius values ​​contribute to obtaining a single-mode optical fiber optimized to operate in the highest wavelengths of the O band. Indeed, the core radius of the single-mode optical fiber according to the invention is smaller than that of the prior art, which makes it possible to obtain a ZDW around 1350 nm. The surface integral of the core 10 can be expressed by the following formula: VOÎ = Jo A n(r) • dr « ~ • [ A nQ • (1+ratio) + A (1- ratio) ] In this formula, the index deltas (An0, An2) are multiplied by 1000, the unit of ri is the pm, and therefore, the unit of VOi is the pm. In a particular embodiment of the invention: 16 pm < VOi < 25 pm. And the volume integral of the soul 10 can be expressed by the following formula: j = 2 • Jo A ta r) ■ r • dr 4- ■ [ A • ( 1 + ratio + ratio2 ) + A n2 • ( 2 - ratio - ratio2 ) ] In this formula, the index deltas (An0, An2) are multiplied by 1000, the unit of ri is the pm and therefore, the unit of Vu is the pm2. In a particular embodiment of the invention: 42 pm2 < Vu <93 pm2. The first coating layer 21 or "intermediate coating" is defined with a radius r2 and a constant refractive index equal to n2. According to one embodiment of the invention, the radius of the first coating layer 21 is preferably defined as follows: 7.8 pm < r2 < 9 pm. The surface integral of the first coating layer 21 can be expressed by the following formula: V02 = fn A n(r) • dr ~ {r2 -r ^) ■ A n2 In this formula the delta index An2 is multiplied by 1000, the unit of ri and r2 is the pm, and therefore the unit of V02 is the pm. In a particular embodiment of the invention: 3 pm < V02 < 12 pm. The volume integral of the first coating layer 21 can be expressed by the following formula: V12 = 2 • A n(r)-r-dr» ( - r^2) • A n2 In this formula, the delta index An2 is multiplied by 1000, the unit of ri and r2 is

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[0097] the pm, and therefore the unit of V12 is the pm2. In a particular embodiment of the invention: 50 pm2 < V12 < 130 pm2. The second coating layer 22, or "trench," is defined with a radius r3 and a constant refractive index n3. The index of the second coating layer is defined as follows: An3 < 0, where An3 is the difference in refractive index between the second coating layer 22 and the third coating layer 23: An3 = n3 - n4 Furthermore, according to a particular embodiment of the invention, the radius of the second coating layer 22 is preferably defined as follows: 10.8 pm < r3 < 13.2 pm. The surface integral of the second coating layer 22 can be expressed by the following formula: V03 = £2 A n(r) • dr « ( r3 - r2 ) • A n3 In this formula, the delta index An3 is multiplied by 1000, the unit of r2 and r3 is the pm, and therefore the unit of V03 is the pm. In a particular embodiment of the invention: -30 pm < V03 < -14 pm. The volume integral of the second coating layer 22 can be expressed by the following formula: V13 - 2 • A n(r) ■ r - dr « (r32 - r22) ■ A n3 In this formula, the delta index An3 is multiplied by 1000, the unit of r2 and r3 is the pm, and therefore the unit of Vi3 is the pm2. In a particular embodiment of the invention: -653 pm2 < V13 < -272 pm2. Thus, the single-mode optical fiber 1 according to the invention requires a trench-assisted design with a refractive index lower than that of the second coating layer to achieve the targeted performance, i.e. a ZDW between 1340 and 1360 nm and a shifted CD and the same other parameters as G.652 and G.657 fibers. Finally, the third coating layer 23 or "external coating" is defined with a constant refractive index n4 which respects the following inequality: n4 > n3. This third coating layer 23 helps to create a trench in the second coating layer 22 and to protect the internal coating layers 20 and the core 10. The third coating layer 23 is preferably composed of almost pure silica, and preferably of pure silica. Specific embodiments of the invention are described below. More particularly, the invention may feature specific refractive index profiles which are described in relation to [Fig.2], [Fig.3], [Fig.4] and [Fig.5], which are not exhaustive examples.

[0098] According to one embodiment of the invention, the refractive index profile of the core 10 and the coating 20 of the optical fiber 1 can be described in relation to profile parameters (Kb K2, K3) which are defined as follows:

[0099] K! = Vn - 5.85 x VOi

[0100] K2 = V02 + 0.65 x Voi

[0101] K3 = V03 - 5 x K2

[0102] In these formulas, the unit of VOi, V02 and V03 is the pm, while the unit of Vu is the pm2. Thus, the formula for Ki can also be expressed as: Ki = Vu - 5.85(pm) x VOi.

[0103] Preferably, according to this embodiment, these profile parameters respect the following inequalities:

[0104] -59 < K! < -47

[0105] 18 <K2<24

[0106] -133 <K3<-118

[0107] These profile parameters thus make it possible to better define the refractive index profile of the optical fiber 1 and also to determine the limits of these profiles. Among the profiles defined by these profile parameters are angular profiles of rectangular or trapezoidal shape, as illustrated by [Fig.2], rounded profiles of overall rectangular or trapezoidal shape, as illustrated by [Fig.3], as well as profiles comprising a core with a central depressed inner zone 11 having either angular or rounded edges, as illustrated by [Fig.4] and [Fig.5].

[0108] Thus, as illustrated by [Fig.3] the index profile of the core 10 can be rounded. In this case, the first region of the core, with a radius r0, ends exactly at the beginning of the decrease in refractive index, that is to say before the rounded part of the profile.

[0109] The coating 20 of the optical fiber 1 may also have a profile with rounded edges. Such an embodiment is not shown in the figures.

[0110] Figure 4 represents another embodiment of the invention, in which the index profile of the web 10 comprises a central internal depressed area 11, in the first region of the web. This figure represents an angular profile.

[0111] More particularly as illustrated in [Fig.4], this internal central depressed zone 11 extends from the center of the core (r = 0) to a radius rD, with rD < r0. In this internal central depressed zone 11, the refractive index n of the core has a minimum value at the center of the core equal to n0D, with n0D < n0, or in other words, An od < An0 with An0D = n0D - n4.

[0112] Figure 5 represents another embodiment of the invention, in which the profile The refractive index of the core (10) is rounded and includes a central depressed area (11). Thus, the entire profile of the core (10), including the central depressed area (11), can have rounded edges. In this case, the central depressed area (11), having a radius rD, terminates when the maximum value (n0, or An0) of the core refractive index (n) is reached. In the embodiment shown in [Fig. 5], rD = r0 since the maximum value of n or An (which is n0, or An0) is reached only at a single point on the graph.

[0113] In one embodiment of the invention, the second region of the core, from radius r0 to radius rb with a decrease in the refractive index, can be obtained by progressively changing the concentration of at least two dopants, which can be chosen from the following elements and / or molecules: - germanium oxide (GeO2) - fluorine (F); - phosphorus oxide (PXOY); - boron oxide (BXOY); - aluminum oxide (Al2O3).

[0114] Modifying the refractive index of the other elements of the optical fiber 1 (other parts of the core 10 and the coating 20) can also be achieved by changing the dopant concentration in these different elements. More particularly, in one embodiment of the invention, the core 10 and the coating 20 of the optical fiber 1 are both composed of silica, and the change in refractive index is achieved by changing the dopant concentration.

[0115] In a preferred embodiment, the impact of the internal depressed central zone 11 on Vu should not induce a reduction in Vu greater than 1 x 10⁻³ pm², or more preferably 0.5 x 10⁻³ pm². Table 2 below shows examples of internal depressed central zones 11 with a fixed An0D.

[0116] [Tables2] rD = Ipm ni® - n0 > - 1 x 10³, and preferably n0D - n0 > - 0.5 x 10³ rD = 0.5pm ni® - n0 > - 4 x 10³, and preferably n0D - n0 > - 2 x 10³ rD = 0.25pm ​​ni® - n0 > - 16 x 10³, and preferably n0D - n0 > - 8 x 10³

[0117] The invention also relates to an optical fiber transmission system comprising an optical fiber 1 having the characteristics described above. Preferably, such a system is an MDWDM system comprising a transmitter and a receiver, each comprising a multiplexer and a demultiplexer, respectively.

[0118] For example, [Fig. 6] represents an MD WM system comprising an optical fiber 1, transmitters Tx, receivers Rx, and optical multiplexers (OM) and demultiplexers (OD). The optical multiplexer and demultiplexer respectively allow multiplexing or concentrating several optical signals at one end of the system (Xb... XN and Xb... XM) and demultiplexing or separating these signals at the other end of the system, in either direction. Thus, the signal propagated in the single-mode optical fiber 1 of the invention is a multiplexed signal (a combination of several signals).

[0119] Optionally, such a system may include repeaters (100-1,..., 100-n) if the system transmits over long distances. The repeaters may include one or more filters, and / or one or more amplifiers 101, and / or one or more dispersion compensation fibers 102, etc.

[0120] By using the optical fiber of the invention, the range of wavelengths that can be used by the optical fiber transmission system is wider than those available for the prior art optical communication system. In fact, it can operate in the O and E wavelength bands (from 1268 to 1375 nm) using, for example, medium wavelength division multiplexing (MWDM) with a 25 Gb / s transceiver.

[0121] In addition, the emitter dispersion penalty of such an optical fiber transmission system is less than 1.5 dB or even less than 0.5 dB.

[0122] Theoretical examples of parameters that can be used to obtain a single-mode optical fiber 1 according to the invention are presented in the tables below.

[0123] Tables 3 to 14 present 94 examples of parameter sets (Exl to Ex94).

[0124] In particular, [Table 3] lists 30 examples (Exl to Ex30) each comprising different ratio parameters (r0 / rj, radii (r0, rb r2, r3), and differences in refractive index with the third coating layer (An0, An2, An3). No. Ratio r0 ri Teq r2 r3 An0 An2 An3 (Units) (pm) (pm) (pm) (pm) (pm) (xlOOO) (xlOOO) (xlOOO) Exl 0.05 0.185 3.7 1.9425 7.83 10.88 8.42 2.18 -4.77 Ex2 0.2 0.730 3.65 2.19 7.83 10.88 7.58 2.18 -4.77 Ex3 0.35 1.222 3.49 2.3557 5 7.83 10.88 7.04 2.2 -4.77 Ex4 0.5 1.635 3.27 2.4525 7.83 10.88 6.73 2.23 -4.77 Ex5 0.75 2.168 2.89 2.5287 5 7.83 10.88 6.49 2.25 -4.77 Ex6 0.95 2.480 2.61 2.5447 5 7.83 10.88 6.43 2.26 -4.77 Ex7 0.05 0.200 3.99 2.0947 5 8.27 10.88 8.18 1.94 -6.27 Ex8 0.2 0.784 3.92 2.352 8.27 10.88 7.35 1.95 -6.27 Ex9 0.35 1.309 3.74 2.5245 8.27 10.88 6.82 1.97 -6.27 ExlO 0.5 1.745 3.49 2.6175 8.27 10.88 6.51 2 -6.27 Exile 0.75 2.303 3.07 2.6862 5 8.27 10.88 6.28 2.03 -6.27 Exl2 0.95 2.632 2.77 2.7007 5 8.27 10.88 6.23 2.03 -6.27 Exl3 0.05 0.212 4.24 2.226 8.7 10.88 8 1.72 -8.39 Exl4 0.2 0.832 4.16 2.496 8.7 10.88 7.17 1.74 -8.39 Exl5 0.35 1.383 3.95 2.6662 5 8.7 10.88 6.65 1.77 -8.39 Exl6 0.5 1.840 3.68 2.76 8.7 10.88 6.35 1.81 -8.39 Exl7 0.75 2.423 3.23 2.8262 5 8.7 10.88 6,13 1,83 -8,39 Exl8 0,95 2,765 2,91 2,8372 5 8,7 10,88 6,07 1,84 -8,39 Exl9 0,05 0,188 3,76 1,974 7,83 11,96 8,28 2,04 -4,35 , Ex20 0,2 0,740 3,7 2,22 7,83 11,96 7,44 2,05 -4,35 Ex21 0,35 1,239 3,54 2,3895 7,83 11,96 6,91 2,07 -4,35 Ex22 0,5 1,655 3,31 2,4825 7,83 11,96 6,59 2,09 -4,35 Ex23 0,75 2,198 2,93 2,5637 5 7,83 11,96 6,34 2,11 -4,35 Ex24 0,95 2,508 2,64 2,574 7,83 11,96 6,29 2,11 -4,35 Ex25 0,05 0,201 4,01 2,1052 5 8,27 11,96 8,06 1,81 -5,74 Ex26 0,2 0,788 3,94 2,364 8,27 11,96 7,23 1,82 -5,74 Ex27 0,35 1,313 3,75 2,5312 5 8,27 11,96 6,7 1,85 -5,74 Ex28 0,5 1,755 3,51 2,6325 8,27 11,96 6,4 1,87 -5,74 Ex29 0,75 2,310 3,08 2,695 8,27 11,96 6,16 1,89 -5,74 Ex30 0,95 2,641 2,78 2,7105 8,27 11,96 6,11 1,9 -5,74

[0126] [Table 4] refers to the same 30 examples as in [Table 3] and represents the surface integrals and volume integrals of the core and cladding layers (Voi, Vu, Vo2, V12, Vos, Vi3). The profile parameters K2 and K3 are also listed in this table. No. v01 Vu Ki V02 k2 v12 V03 V13 k3 (Units) (pm) (pn2) (pn2) (pm) (pm) (pn2) (pm) (pn2) (pm) Exl 20.2 59.8 -58.3 9.0 22.1 103.8 -14.5 -272.2 -125.2 Ex2 19.8 58.8 -57.0 9.1 22.0 104.6 -14.5 -272.2 -124.4 Ex3 19.1 55.7 -55.9 9.5 21.9 108.1 -14.5 -272.2 -124.3 Ex4 18.3 51.9 -55.3 10.2 22.1 112.9 -14.5 -272.2 -125.0 Ex5 17.2 46.1 -54.7 11.1 22.3 119.2 -14.5 -272.2 -126.1 Ex6 16.5 42.4 -54.2 11.8 22.5 123.2 -14.5 -272.2 -127.2 Ex7 20.8 65.7 -56.0 8.3 21.8 101.8 -16.4 -313.4 -125.5 Ex8 20.3 64.3 -54.8 8.5 21.7 103.4 -16.4 -313.4 -124.9 Ex9 19.6 60.9 -53.9 8.9 21.7 107.2 -16.4 -313.4 -124.7 ExlO 18.8 56.4 -53.5 9.6 21.8 112.4 -16.4 -313.4 -125.2 Exile 17.6 50.0 -53.2 10.6 22.0 119.7 -16.4 -313.4 -126.5 Exl2 17.0 46.2 -53.0 11.2 22.2 123.3 -16.4 -313.4 -127.3 Exl3 21.3 70.5 -53.9 7.7 21.5 99.3 -18.3 -358, 1 -125, 8 Exl4 20.8 69.0 -52.7 7.9 21.4 101.6 -18.3 -358.1 -125.4 Exl5 20.0 65.0 -52.0 8.4 21.4 106.4 -18.3 -358.1 -125.3 Exl6 19,2 60,4 -51,9 9,1 21,6 112,5 -18,3 -358, 1 -126, 1 Exl7 18,1 53,7 -52,0 10,0 21,8 119,4 -18,3 -358, 1 -127, 0 Exl8 17,4 49,6 -51,9 10,7 21,9 123,7 -18,3 -358, 1 -128, 0 Exl9 20,0 59,8 -57,1 8,3 21,3 96,2 -18,0 -355, 5 -124, 4 Ex20 19,6 58,6 -55,8 8,5 21,2 97,6 -18,0 -355, 5 -123, 8 Ex21 18,9 55,7 -54,8 8,9 21,2 101,0 -18,0 -355, 5 -123, 8 Ex22 18,1 51,7 -54,2 9,4 21,2 105,2 -18,0 -355, 5 -124, 0 Ex23 17,0 46,1 -53,5 10,3 21,4 111,2 -18,0 -355, 5 -125, 0 Ex24 16,3 42,4 -53,1 11,0 21,6 114,7 -18,0 -355, 5 -125, 8 Ex25 20,4 64,4 -55,1 7,7 21,0 94,7 -21,2 -428, 5 -126, 1 Ex26 20,0 63,0 -53,8 7,9 20,9 96,2 -21,2 -428, 5 -125, 5 Ex27 19,2 59,5 -52,9 8,4 20,9 100,5 -21,2 -428, 5 -125, 4 Ex28 18,5 55,6 -52,6 8,9 20,9 104,9 -21,2 -428, 5 -125, 8 Ex29 17,3 49,2 -52,2 9,8 21,1 111,3 -21,2 -428, 5 -126, 5 Ex30 16,7 45,6 -52,0 10,4 21,3 115,3 -21,2 -428, 5 -127, 6

[0128] [Table 5] refers to the same 30 examples in [Table 3] and represents the corresponding zero-dispersion wavelength (ZDW), zero-dispersion shift (ZDS), chromatic dispersion (CD) at 1267.5 nm, 1310 nm, and 1374.5 nm, and mode field diameter (MFD) at 1310 nm and 1550 nm, and the cable cutoff wavelength. No. ZD W ZDS CD 1267.5 CD 1310 CD 1374.5 MFD 1310 MFD 1550 Cutoff Wavelength (Units) (nm) (ps / nm²-km) (ps / nm-km) (ps / nm-km) (ps / nm-km) (pm) (pm) (nm) Ex1 1350 0.097 -8.9 -4.1 2.4 9.00 10.33 1212 Ex2 1350 0.096 -8.9 -4.1 2.4 9.00 10.33 1211 Ex3 1350 0.096 -8.8 -4.1 2.3 9.00 10.33 1211 Ex4 1350 0.096 -8.8 -4.1 2.4 9.00 10.34 1212 Ex5 1350 0.096 -8.8 -4.1 2.3 9.00 10.33 1214 Ex6 1350 0.096 -8.7 -4.1 2.4 9.00 10.34 1214 Ex7 1350 0.096 -8.8 -4.1 2.4 9.00 10.34 1209 Ex8 1350 0.096 -8.8 -4.1 2.3 9.00 10.34 1209 Ex9 1350 0.096 -8.8 -4.1 2.3 9.00 10.34 1209 ExlO 1350 0.095 -8.7 -4.1 2.3 9.00 10.35 1210 Exile 1350 0.095 -8.7 -4 2.3 9.01 10.35 1210 Exl2 1350 0.095 -8.7 -4.1 2.3 9.00 10.35 1210 Exl3 1350 0.095 -8.7 -4.1 2.3 9.00 10.34 1209 Exl4 1350 0.095 -8.7 -4.1 2.3 9.00 10.34 1209 Exl5 1350 0.095 -8.7 -4 2.3 9.00 10.34 1209 Exl6 1350 0.095 -8.6 -4 2.3 9.01 10.35 1209 Exl7 1350 0.094 -8.6 -4 2.3 8.99 10.34 1209 Exl8 1350 0.094 -8.6 -4 2.3 9.00 10.35 1209 Exl9 1350 0.097 -8.9 -4,1 2.4 9.00 10.33 1210 Ex20 1350 0.097 -8.8 -4.1 2.4 9.00 10.34 1210 Ex21 1350 0.096 -8.8 -4.1 2.3 8.99 10.33 1210 Ex22 1350 0.096 -8.8 -4.1 2.4 9.00 10.34 1210 Ex23 1350 0.096 -8.7 -4 2.4 9.00 10.34 1208 , Ex24 1350 0.096 -8.8 -4.1 2.3 9.00 10.34 1209 Ex25 1350 0.097 -8.8 -4.1 2.4 9.00 10.34 1213 Ex26 1350 0.096 -8.8 -4.1 2.4 9.00 10.34 1212 Ex27 1350 0.096 -8.8 -4.1 2.4 9.01 10.34 1213 Ex28 1350 0.096 -8.7 -4.1 2.3 9.00 10.33 1213 Ex29 1350 0.096 -8.7 -4.1 2.3 9.00 10.34 1212 Ex30 1350 0.095 -8.7 -4.1 2.3 9.00 10.34 1212

[0130] [Table 6] refers to the same 30 examples in [Table 3] and represents the corresponding bending losses (R7.5BL, R10BL and R15BL) for 1 or 10 turns, measured at different wavelengths (1550 pm and 1625 pm), and for different radii (7.5 mm, 10 mm and 15 mm). No. R15BL to 1550 R10BL to 1550 R7.5BL to 1550 R15BL to 1625 R10BL to 1625 R7.5BL to 1625 BL Type (Units) (dB / 10 revolutions) (dB / revolution) (dB / revolution) (dB / 10 revolutions) (dB / revolution) (dB / revolution) Exl 0.034 0.16 0.92 0.184 0.47 1.94 Al Ex2 0.035 0.16 0.93 0.189 0.48 1.96 Al Ex3 0.035 0.17 0.94 0.191 0.48 1.97 Al Ex4 0.036 0.17 0.95 0.194 0.49 1.99 Al Ex5 0.035 0.17 0.95 0.192 0.48 1.99 Al Ex6 0.036 0.17 0.95 0.193 0.49 2 Al Ex7 0.035 0.16 0.84 0.189 0.45 1.75 Al Ex8 0.036 0.16 0.85 0.191 0.45 1.76 Al Ex9 0.037 0.16 0.86 0.196 0.46 1.79 Al ExlO 0.037 0.16 0.87 0.198 0.46 1.81 Al Exile 0.039 0.17 0.9 0.207 0.48 1.85 Al Exl2 0.04 0.17 0.9 0.21 0.48 1.86 Al Exl3 0.035 0.14 0.75 0.184 0.41 1.56 Al Exl4 0.036 0.15 0.76 0.188 0.42 1.57 Al Exl5 0.037 0.15 0.78 0.192 0.42 1.6 Al Exl6 0.038 0.15 0.8 0.199 0.43 1.63 Al Exl7 0.041 0.16 0.83 0.213 0.45 1.69 Al Exl8 0.042 0.16 0.84 0.217 0.46 1.71 Al Exl9 0.043 0.15 0.7 0.218 0.41 1.42 Al Ex20 0.042 0.15 0.7 0.217 0.41 1.42 Al Ex21 0.043 0.15 0.7 0.219 0.41 1.43 Al Ex22 0.045 0.15 0.72 0.228 0.42 1.46 Al Ex23 0.048 0.16 0.75 0.244 0.44 1.52 Al Ex24 0.048 0.16 0.75 0.245 0.44 1.51 Al Ex25 0.043 0.13 0.57 0.213 0.35 1.15 Al Ex26 0.043 0.13 0.58 0.217 0.36 1.16 Al . Ex27 0.043 0.13 0.58 0.217 0.36 1.17 Al Ex28 0.045 0.13 0.59 0.223 0.37 1.19 Al Ex29 0.049 0.14 0.62 0.241 0.38 1.24 Al Ex30 0.05 0.14 0.63 0.247 0.39 1.25 Al

[0132] [Table 7], [Table 8] and [Table 9] represent 30 additional examples (Ex31 to Ex60), listing the same parameters as respectively [Table 3], [Table 4], [Table 5] and [Table 6]. N° Ratio r0 ri Teq r2 r3 An0 An2 An3 (Unités ) (pm) (pm) (pm) (pm) (pm) (xlOOO ) (xlOOO ) (xlOOO ) Ex31 0,05 0,212 4,24 2,226 8,7 11,96 7,89 1,59 -7,58 Ex32 0,2 0,832 4,16 2,496 8,7 11,96 7,05 1,6 -7,58 Ex33 0,35 1,383 3,95 2,66625 8,7 11,96 6,54 1,65 -7,58 Ex34 0,5 1,840 3,68 2,76 8,7 11,96 6,24 1,68 -7,58 Ex35 0,75 2,423 3,23 2,82625 8,7 11,96 6 1,7 -7,58 Ex36 0,95 2,765 2,91 2,83725 8,7 11,96 5,95 1,7 -7,58 Ex37 0,05 0,194 3,87 2,03175 7,83 13,05 8,11 1,9 -3,95 Ex38 0,2 0,762 3,81 2,286 7,83 13,05 7,27 1,9 -3,95 Ex39 0,35 1,274 3,64 2,457 7,83 13,05 6,76 1,94 -3,95 Ex40 0,5 1,700 3,4 2,55 7,83 13,05 6,45 1,97 -3,95 Ex41 0,75 2,250 3 2,625 7,83 13,05 6,21 1,98 -3,95 Ex42 0,95 2,575 2,71 2,64225 7,83 13,05 6,15 1,99 -3,95 Ex43 0,05 0,204 4,08 2,142 8,27 13,05 7,95 1,7 -5,25 Ex44 0,2 0,804 4,02 2,412 8,27 13,05 7,12 1,71 -5,25 Ex45 0,35 1,337 3,82 2,5785 8,27 13,05 6,6 1,74 -5,25 Ex46 0,5 1,780 3,56 2,67 8,27 13,05 6,29 1,77 -5,25 Ex47 0,75 2,348 3,13 2,73875 8,27 13,05 6,06 1,79 -5,25 Ex48 0,95 2,689 2,83 2,75925 8,27 13,05 6 1,79 -5,25 Ex49 0,05 0,215 4,3 2,2575 8,7 13,05 7,78 1,48 -6,9 Ex50 0,2 0,844 4,22 2,532 8,7 13,05 6,95 1,5 -6,9 Ex51 0,35 1,400 4 2,7 8,7 13,05 6,44 1,54 -6,9 Ex52 0,5 1,860 3,72 2,79 8,7 13,05 6,14 1,57 -6,9 Ex53 0,75 2,445 3,26 2,8525 8,7 13,05 5,91 1,6 -6,9 Ex54 0,95 2,793 2,94 2,8665 8,7 13,05 5,86 1,61 -6,9 Ex55 0,45 1,481 3,29 2,38525 8,27 13,05 6,54 1,95 -5,25 Ex56 0,25 0,908 3,63 2,26875 8,27 13,05 7,18 1,86 -5,25 Ex57 0,4 1,352 3,38 2,366 7,83 13,05 6,54 1,93 -3,95 , Ex58 0,7 2,072 2,96 2,516 7,83 11,96 6,55 2,28 -4,35 Ex59 0,15 0,593 3,95 2,27125 8,27 10,88 7,73 2,05 -6,27 Ex60 0,1 0,390 3,9 2,145 7,83 10,88 7,92 2,19 -4,77 No. v01 Vu Ki V02 k2 v12 V03 V13 k3 (Units) (pm) (pn2) (pn2) (pm) (pm) (pn2) (pm) (pn2) (pm) Ex31 20.8 68.3 -53.2 7.1 20.6 91.8 -24.7 -510.5 -127.7 Ex32 20.3 66.7 -51.8 7.3 20.4 93.4 -24.7 -510.5 -126.9 Ex33 19.6 63.2 -51.2 7.8 20.5 99.1 -24.7 -510.5 -127.5 Ex34 18.8 58.8 -51.0 8.4 20.6 104.4 -24.7 -510.5 -127.9 Ex35 17.6 52.3 -50.9 9.3 20.8 110.9 -24.7 -510.5 -128.5 Ex36 17.0 48.6 -50.9 9.8 20.9 114.3 -24.7 -510.5 -129.2 FY37 20.0 61.1 -55.7 7.5 20.5 88.0 -20.6 -430.5 -123.1 FY38 19.5 59.8 -54.4 7.6 20.3 88.9 -20.6 -430.5 -122.2 FY39 18.9 57.1 -53.5 8.1 20.4 93.2 -20.6 -430.5 -122.7 Ex40 18.1 53.0 -53.0 8.7 20.5 98.0 -20.6 -430.5 -123.2 Ex41 17.0 47.2 -52.5 9.6 20.6 103.6 -20.6 -430.5 -123.8 Ex42 16.4 43.7 -52.2 10.2 20.8 107.4 -20.6 -430.5 -124.8 Ex43 20.3 64.8 -54.1 7.1 20.3 88.0 -25.1 -535.0 -126.8 Ex44 19.9 63.8 -52.8 7.3 20.2 89.3 -25.1 -535.0 -126.2 Ex45 19.2 60.2 -52.0 7.7 20.2 93.6 -25.1 -535.0 -126.1 Ex46 18.4 55.8 -51.6 8.3 20.3 98.6 -25.1 -535.0 -126.5 Ex47 17.3 49.8 -51,4 9,2 20,4 104,9 -25,1 -535,0 -127,3 Ex48 16,7 46,4 -51,2 9,7 20,6 108,1 -25,1 -535,0 -128,0 Ex49 20,6 68,2 -52,2 6,5 19,9 84,7 -30,0 -652,8 -129,5 Ex50 20,1 66,8 -50,9 6,7 19,8 86,8 -30,0 -652,8 -129,0 Ex51 19,4 63,1 -50,3 7,2 19,8 91,9 -30,0 -652,8 -129,2 Ex52 18,6 58,6 -50,1 7,8 19,9 97,1 -30,0 -652,8 -129,5 Ex53 17,5 52,3 -50,1 8,7 20,1 104,1 -30,0 -652,8 -130,4 Ex54 16,9 48,8 -50,1 9,3 20,3 107,9 -30,0 -652,8 -131,4 Ex55 17,4 48,5 -53,1 9,7 21,0 112,3 -25,1 -535,0 -130,1 Ex56 18,8 55,2 -54,9 8,6 20,9 102,7 -25,1 -535,0 -129,4 Ex57 17,4 49,4 -52,5 8,6 19,9 96,3 -20,6 -430,5 -120,2 , Ex58 17,5 47,3 -55,0 11,1 22,5 119,8 -18,0 -355,5 -130,3 Ex59 21,0 66,6 -56,2 8,9 22,5 108,2 -16,4 -313,4 -128,9 Ex60 20,8 65,6 -56,3 8,6 22,1 101,0 -14,5 -272,2 -125,3 No. ZD W ZDS CD 1267.5 CD 1310 CD 1374.5 MF D 1310 MFD 1550 Cutoff Wavelength (Units) (nm) (ps / nm²-km) (ps / nm-k m) (ps / nm-k m) (ps / nm-k m) (pm) (pm) (nm) Ex31 1350 0.096 -8.8 -4.1 2.3 8.99 10.33 1216 Ex32 1350 0.096 -8.7 -4.1 2.3 9.00 10.33 1215 Ex33 1350 0.096 -8.7 -4 2.3 9.00 10.34 1219 Ex34 1350 0.095 -8.6 -4 2.3 9.00 10.34 1218 Ex35 1350 0.095 -8.6 -4 2.3 9.00 10.35 1215 Ex36 1350 0.095 -8.6 -4 2.3 9.00 10.34 1215 Ex37 1350 0.096 -8.8 -4.1 2.4 9.00 10.34 1214 Ex38 1350 0.096 -8.8 -4.1 2.4 9.00 10.34 1213 Ex39 1350 0.096 -8.8 -4.1 2.3 9.00 10.34 1218 Ex40 1350 0.096 -8.7 -4 2.4 9.00 10.35 1219 Ex41 1350 0.095 -8.7 -4 2.3 9.00 10.34 1217 Ex42 1350 0.095 -8.7 -4 2.4 9.00 10.35 1216 Ex43 1350 0.096 -8.8 -4.1 2.3 9.00 10.34 1214 Ex44 1350 0,096 -8,8 -4,1 2,3 9,00 10,34 1215 Ex45 1350 0,096 -8,7 -4,1 2,3 9,00 10,34 1218 Ex46 1350 0,095 -8,7 -4 2,3 9,01 10,35 1213 Ex47 1350 0,095 -8,7 -4 2,3 9,00 10,35 1214 Ex48 1350 0,095 -8,6 -4 2,3 9,00 10,34 1214 Ex49 1350 0,096 -8,7 -4,1 2,3 9,00 10,34 1205 Ex50 1350 0,096 -8,7 -4 2,3 9,00 10,34 1205 Ex51 1350 0,095 -8,7 -4 2,3 9,00 10,34 1207 Ex52 1350 0,095 -8,6 -4 2,3 9,00 10,34 1206 Ex53 1350 0,095 -8,6 -4 2,3 9,00 10,35 1206 Ex54 1350 0,095 -8,6 -4 2,3 9,00 10,35 1206 Ex55 1352 0,098 -9,3 -4,4 2,2 9,18 10,58 1221 Ex56 1356 0,097 -9,5 -4,7 1,8 9,03 10,43 1215 Ex57 1350 0,097 -8,8 -4,1 2,4 9,15 10,52 1186 Ex58 1350 0,096 -8,8 -4,1 2,4 9,01 10,35 1245 Ex59 1351 0,096 -8,9 -4,2 2,3 8,98 10,31 1237 Ex60 1345 0,096 -8,3 -3,6 2,8 9,04 10,33 1229 No. R15BL to 1550 R10BL to 1550 R7.5BL to 1550 R15BL to 1625 R10BL to 1625 R7.5BL to 1625 BL Type (Units) (dB / rev) (dB / rev) (dB / rev) (dB / rev) (dB / rev) (dB / rev) Ex31 0.04 0.11 0.46 0.197 0.29 0.91 Al Ex32 0.041 0.11 0.46 0.203 0.3 0.93 Al Ex33 0.039 0.11 0.46 0.194 0.29 0.92 Al Ex34 0.043 0.11 0.48 0.21 0.31 0.95 Al Ex35 0.048 0.12 0.5 0.232 0.33 1 Al Ex36 0.049 0.12 0.51 0.236 0.33 1.01 Al Ex37 0.046 0.12 0.51 0.224 0.33 1.02 Al Ex38 0.047 0.12 0.51 0.229 0.33 1.03 Al Ex39 0.043 0.12 0.5 0.213 0.32 1.01 Al Ex40 0.044 0.12 0.51 0.219 0.33 1.02 Al Ex41 0.048 0.13 0.52 0.236 0.34 1.05 Al Ex42 0.049 0.13 0.53 0.241 0.35 1.07 Al Ex43 0.036 0.09 0.34 0.177 0.24 0.69 Al Ex44 0.036 0.09 0.34 0.177 0.24 0.69 Al Ex45 0.037 0.09 0.35 0.18 0.24 0.7 Al Ex46 0.04 0.09 0.36 0.192 0.25 0.72 Al Ex47 0.042 0.1 0.37 0.202 0.26 0.74 Al Ex48 0.043 0.1 0.37 0.206 0.26 0.74 Al Ex49 0.031 0.07 0.24 0.151 0.18 0.48 Al Ex50 0.031 0.07 0.24 0.151 0.18 0.48 Al Ex51 0.032 0.07 0.24 0.152 0.18 0.49 Al Ex52 0.034 0.07 0.25 0.163 0.19 0.51 Al Ex53 0.037 0.07 0.26 0.173 0.19 0.52 Al Ex54 0.037 0.07 0.26 0.176 0.19 0.52 Al Ex55 0.071 0.13 0.48 0.310 0.34 0.92 Al. Ex56 0.052 0.11 0.42 0.241 0.29 0.82 Al Ex57 0.150 0.24 0.83 0.636 0.59 1.57 Al Ex58 0.018 0.09 0.51 0.101 0.27 1.09 Al Ex59 0.015 0.09 0.60 0.089 0.28 1.31 Al Ex60 0.018 0.11 0.71 0.106 0.33 1.55 Al

[0137] Finally, [Table 11], [Table 12], [Table 13] and [Table 14] represent 34 additional examples (Ex61 to Ex94), listing the same parameters as [Table 3], [Table 4], [Table 5] and [Table 6], respectively. No. Ratio r0 ri Teq r2 r3 An0 An2 An3 (Units) (pm) (pm) (pm) (pm) (pm) xlOOO xlOOO xlOOO Ex61 0.5 1.610 3.22 2.415 7.83 10.88 7.04 2.38 -4.77 Ex62 0.3 1.062 3.54 2.301 8.27 11.96 7.04 2.09 -5.74 Ex63 0.6 1.938 3.23 2.584 7.83 10.88 6.47 1.99 -4.77 Ex64 0.3 1.236 4.12 2.678 8.27 10.88 6.9 1.76 -6.27 Ex65 0.25 0.785 3.14 1.9625 7.83 10.88 7.66 2.33 -4.77 Ex66 0.1 0.407 4.07 2.2385 7.83 10.88 7.72 2.05 -4.77 Ex67 0.25 0.928 3.71 2.3187 5 7.83 10.88 7.25 2.39 -4.77 Ex68 0.95 2.584 2.72 2.652 7.83 10.88 6.18 2.28 -4.77 Ex69 0.7 2.289 3.27 2.7795 8.7 10.88 6.27 1.98 -8.39 Ex70 0.7 2.156 3.08 2.618 7.83 13.05 6.58 2.16 -3.95 Ex71 0.1 0.506 5.06 2.783 8.27 13.05 7.74 1.18 -5.25 Ex72 0.2 0.828 4.14 2.484 7.83 11.96 7.43 1.94 -4.35 Ex73 0.3 1.332 4.44 2.886 8.27 13.05 6.39 1.43 -5.25 Ex74 0.1 0.441 4.41 2.4255 8.7 13.05 7.39 1.6 -6.9 Ex75 0.4 1.652 4.13 2.891 8.7 13.05 6.48 1.21 -6.9 Ex76 0.5 1.720 3.44 2.58 7.83 13.05 6.39 2.17 -3.95 Ex77 0.1 0.480 4.8 2.64 8.27 10.88 7.86 1.66 -6.27 Ex78 0,6 2.292 3.82 3.056 7.83 11.96 6.54 1.87 -4.35 Ex79 0.9 2.763 3.07 2.9165 8.27 10.88 6.21 2.13 -6.27 Ex80 0.4 1.612 4.03 2.821 8.27 11.96 6.44 1.82 -5.74 Ex81 0.45 1.899 4.22 3.0595 8.27 13.05 6.17 1.4 -5.25, Ex82 0.4 1.664 4.16 2.912 8.27 13.05 6.55 1.34 -5.25 Ex83 0.3 1.305 4.35 2.8275 8.7 11.96 6.54 1.65 -7.58 Ex84 0.6 2.394 3.99 3.192 8.7 11.96 6.15 1.44 -7.58 Ex85 0.7 2.345 3.35 2.8475 8.7 11.96 6.42 1.6 -7.58 Ex86 0.1 0.434 4.34 2.387 7.83 13.05 8.16 1.76 -3.95 Ex87 0.85 2.992 3.52 3.256 8.7 13.05 5.99 1.23 -6.9 Ex88 0.1 0.448 4.48 2.464 8.7 10.88 7.93 1.74 -8.39 Ex89 0.25 1.150 4.6 2.875 8.27 10.88 7.11 1.74 -6.27 Ex90 0.2 0.894 4.47 2.682 7.83 11.96 7.15 1.74 -4.35 Ex91 0.45 1.733 3.85 2.7912 5 8.7 11.96 6.75 1.57 -7.58 Ex92 0.9 2.790 3.1 2.945 8.27 13.05 6.09 1.69 -5.25 Ex93 0.75 2.790 3.72 3.255 8.7 11.96 6.26 1.44 -7.58 Ex94 0.25 1.070 4.28 2.675 7.83 10.88 7.53 2.04 -4'.77

[0139] [Tables 12] No. v01 Vu Ki V02 k2 v12 V03 V13 k3 (Units) (pm) (pn2) (pn2) (pm) (pm) (pn2) (pm) (pn2) (pm) Ex61 18.9 52.9 -57.8 11.0 23.3 121.2 -14.5 -272.2 -130.9 Ex62 18.8 54.9 -55.0 9.9 22.1 116.8 -21.2 -428.5 -131.7 Ex63 18.0 51.3 -54.0 9.2 20.9 101.2 -14.5 -272.2 -118.8 Ex64 21.0 70.3 -52.6 7.3 21.0 90.5 -16.4 -313.4 -121.2 Ex65 17.8 46.0 -58.0 10.9 22.5 119.9 -14.5 -272.2 -127.0 Ex66 21.0 68.7 -54.3 7.7 21.4 91.7 -14.5 -272.2 -121.5 Ex67 20.1 62.2 -55.6 9.8 22.9 113.6 -14.5 -272.2 -129.2 Ex68 16.5 44.3 -52.5 11.7 22.4 122.9 -14.5 -272.2 -126.6 Ex69 18.4 54.7 -53.0 10.8 22.7 128.7 -18.3 -358.1 -131.8 Ex70 18.2 51.1 -55.5 10.3 22.1 111.9 -20.6 -430.5 -131.1 Ex71 24.2 92.4 -49.4 3.8 19.5 50.5 -25.1 -535.0 -122.8 Ex72 21.7 72.1 -54.6 7.2 21.2 85.7 -18.0 -355.5 -124.2 Ex73 20.7 73.5 -47.4 5.5 18.9 69.6 -25.1 -535.0 -119.6 Ex74 21.1 72.8 -50.7 6.9 20.6 90.0 -30.0 -652.8 -132.9 Ex75 20.2 67.4 -51.0 5.5 18.7 70.9 -30.0 -652.8 -123.4 Ex76 18.4 54.8 -52.6 9.5 21.5 107.4 -20.6 -430.5 -127.9 Ex77 24.3 91,1 -51,3 5,8 21,6 75,3 -16,4 -313,4 -124,3 Ex78 21,4 71,8 -53,5 7,5 21,4 87,4 -18,0 -355,5 -125,1 Ex79 18,4 54,8 -53,1 11,1 23,1 125,6 -16,4 -313,4 -131,7 Ex80 20,4 68,6 -50,6 7,7 21,0 94,9 -21,2 -428,5 -126,0 Ex81 20,5 71,7 -48,2 5,7 19,0 70,8 -25,1 -535,0 -120,1 Ex82 20,7 70,1 -51,3 5,5 19,0 68,5 -25,1 -535,0 -120,1 Ex83 21,0 74,1 -48,8 7,2 20,8 93,7 -24,7 -510,5 -128,9 Ex84 20,8 71,9 -49,6 6,8 20,3 86,1 -24,7 -510,5 -126,2 Ex85 19,1 57,4 -54,2 8,6 21,0 103,1 -24,7 -510,5 -129,5 Ex86 22,9 77,8 -56,3 6,1 21,0 74,8 -20,6 -430,5 -125,8 Ex87 19,8 65,8 -50,2 6,4 19,3 77,9 -30,0 -652,8 -126,3 , Ex88 23,0 80,9 -53,9 7,3 22,3 96,8 -18,3 -358,1 -129,9 Ex89 23,4 86,5 -50,6 6,4 21,6 82,2 -16,4 -313,4 -124,5 Ex90 22,3 79,4 -50,9 5,8 20,3 71,9 -18,0 -355,5 -119,6 Ex91 20,5 65,6 -54,4 7,6 20,9 95,6 -24,7 -510,5 -129,4 Ex92 18,2 54,4 -52,0 8,7 20,6 99,3 -25,1 -535,0 -127,9 Ex93 21,0 71,3 -51,8 7,2 20,9 89,1 -24,7 -510,5 -129,0 Ex94 23,4 81,4 -55,6 7,2 22,5 87,7 -14,5 -272,2 -126,9

[0140] [Tables 13] No. ZD W ZDS CD 1267.5 CD 1310 CD 1374.5 MFD 1310 MF D 1550 Cutoff Wavelength (Units s) (nm) (ps / nm²-km) (ps / nm-km) (ps / nm-km) (ps / nm-km) (pm) (pm) (nm) Ex61 135 4 0.096 -9.3 -4.5 2.0 8.90 10.2 4 1247 Ex62 135 0 0.098 -9.0 -4.2 2.4 9.16 10.5 2 1244 Ex63 135 2 0.094 -8.9 -4.2 2.1 8.87 10.2 0 1170 Ex64 134 8 0.094 -8.4 -3.8 2.5 8.84 10.1 3 1200 Ex65 135 2 0.099 -9.4 -4.5 2.2 9.18 10.5 8 1209 Ex66 134 2 0.096 -7.9 -3.3 3.0 9.03 10.3 0 1212 Ex67 134 2 0.097 -8.0 -3.3 3.1 9.16 10.4 4 1259 Ex68 134 1 0.096 -7.8 -3.2 3.1 9.16 10.4 5 1224 Ex69 135 0 0.095 -8.7 -4.0 2.3 9.04 10.3 9 1239 Ex70 135 4 0.095 -9.0 -4.4 2.0 8.86 10.2 0 1260 Ex71 134 2 0.093 -7.6 -3.1 3.0 8.64 9.82 1244 Ex72 134 7 0.095 -8.3 -3.7 2.6 8.82 10.0 8 1233 Ex73 134 0.094 -7.5 -3.0 3.2 8.97 10.2 1200 0 1 Ex74 134 5 0,096 -8,2 -3,6 2,8 9,10 10,4 0 1246 Ex75 135 4 0,092 -8,7 -4,3 1,9 8,62 9,92 1175 Ex76 134 3 0,096 -8,0 -3,4 3,0 9,18 10,4 8 1260 Ex77 134 2 0,094 -7,7 -3,1 3,0 8,77 9,97 1252 Ex78 134 1 0,092 -7,4 -3,0 3,0 8,65 9,83 1256 Ex79 134 2 0,094 -7,7 -3,2 3,0 9,02 10,2 9 1259 Ex80 134 2 0,095 -7,8 -3,2 3,0 9,00 10,2 6 1240 Ex81 134 1 0,093 -7,4 -3,0 3,1 8,83 10,0 6 1204 Ex82 135 0 0,092 -8,3 -3,9 2,2 8,61 9,88 1185 Ex83 134 2 0,095 -7,8 -3,2 3,1 9,06 10,3 3 1247 Ex84 134 1 0,092 -7,3 -3,0 3,1 8,76 9,97 1239 Ex85 135 9 0,092 -9,3 -4,8 1,4 8,61 9,95 1211 Ex86 135 2 0,093 -8,7 -4,2 2,1 8,63 9,89 1245 Ex87 134 2 0,090 -7,3 -3,0 2,9 8,63 9,83 1220 Ex88 135 0 0,094 -8,6 -4,0 2,3 8,83 10,1 3 1250 Ex89 134 1 0,093 -7,6 -3,1 3,1 8,79 10,0 1 1252 Ex90 134 0,094 -7,6 -3,1 3,1 8,84 10,0 1226 1 6 Ex91 135 9 0.093 -9.3 -4.8 1.5 8.60 9.93 1216 Ex92 134 8 0.093 -8.2 -3.7 2.4 8.80 10.0 9 1222 Ex93 134 1 0.090 -7.3 -3.0 3.0 8.61 9.80 1257 Ex94 134 7 0.093 -8.2 -3.6 2.6 8.65 9.87 1260

[0141] [Tables 14] N° R15BL to 1550 R10BL to 1550 R7.5BL to 1550 R15BL to 1625 R10BL to 1625 R7.5BL to 1625 Type of BL (Unités) (dB / lOtours) (dB / tour) (dB / tour) (dB / lOtours) ) (dB / tour) (dB / tour) Ex61 0.009 0.07 0.54 0.057 0.23 1.24 Al Ex62 0.037 0.12 0.58 0.180 0.34 1.16 Al Ex63 0.072 0.25 1.22 0.370 0.70 2.49 Al Ex64 0.021 0.11 0.63 0.121 0.33 1.38 Al Ex65 0.098 0.32 1.53 0.459 0.84 2.97 Al Ex66 0.027 0.14 0.81 0.149 0.40 1.73 Al Ex67 0.011 0.08 0.60 0.067 0.25 1.34 Al Ex68 0.035 0.17 0.95 0.183 0.47 1.97 Al Ex69 0.021 0.11 0.65 0.117 0.32 1.37 Al Ex70 0.008 0.04 0.25 0.048 0.14 0.57 A2 Ex71 0.002 0.01 0.09 0.013 0.05 0.22 A2 Ex72 0.008 0.05 0.33 0.050 0.16 0.77 A2 Ex73 0.027 0.07 0.28 0.136 0.20 0.58 A2 Ex74 0.015 0.04 0.19 0.078 0.13 0.38 A2 Ex75 0.019 0.05 0.18 0.103 0.13 0.37 A2 Ex76 0.021 0.08 0.38 0.107 0.22 0.80 A2 Ex77 0.002 0.02 0.23 0.013 0.08 0.57 A2 Ex78 0.001 0.02 0.15 0.010 0.06 0.39 A2 Ex79 0.006 0.06 0.43 0.042 0.18 0.98 A2 Ex80 0.013 0.06 0.35 0.076 0.19 0.76 A2 Ex81 0.014 0.05 0.21 0.080 0.14 0.46 A2 Ex82 0.013 0.04 0.20 0.079 0.14 0.45 A2 Ex83 0.014 0.06 0.29 0.075 0.17 0.62 A2 Ex84 0.005 0.03 0.18 0.032 0.10 0.41 A2 Ex85 0.012 0.05 0.27 0.074 0.16 0.59 A2 Ex86 0.003 0.02 0.15 0.020 0.07 0.37 A2 . Ex87 0.004 0.02 0.10 0.029 0.06 0.23 A2 Ex88 0.004 0.04 0.31 0.030 0.13 0.75 A2 Ex89 0.002 0.02 0.24 0.015 0.09 0.60 A2 Ex90 0.008 0.05 0.33 0.053 0.17 0.76 A2 Ex91 0.008 0.04 0.23 0.053 0.13 0.52 A2 Ex92 0.012 0.05 0.21 0.070 0.14 0.47 A2 Ex93 0.001 0.01 0.11 0.011 0.05 0.27 A2 Ex94 0.001 0.01 0.18 0.007 0.06 0.48 A2

[0142] The ranges of values ​​of the different parameters used in the 94 examples listed in the tables above are presented below, in [Table 15], [Table 16], [Table 17] and [Table 18].

[0143] [Tables 15] Parameter r0 / ri r0 ri Teq r2 r3 An0 An2 An3 Units pm pm pm pm pm (xlOOO ) (xlOOO ) (xlOOO ) Minimum value 0.05 0.19 2.61 1.94 7.83 10.88 5.86 1.18 7.83 Maximum value -95. 2.99 5.06 3.26 8.70 13.05 8.42 2.39 -3.95

[0144] [Tables 16] Parameter v01 Vu V02 v12 V03 Vu Ki k2 k3 Units (pm) (pm2) (pm2) (pm) (pm) (pm2) (pm) (pm2) (pm) Minimum value 16.3 42.4 3.8 50.5 -30 -652.8 -58.3 Maximum value -18.23.94. 92.4 11.8 128.7 -14.5 -277.2 -47.4 23.3 -118.8

[0145] [Table7] Parameters ZDW ZDS CD 1267.5 CD 1310 CD 1374.5 MFD 1310 MFD 1550 Cut-off wavelength Units nm ps / nm2-km ps / nm2-km ps / nm2-km ps / nm2-km m ppm 130 Minimum value 0.090 -9.5 -4.8 1.4 8.6 9.8 1170 Maximum value 1359 0.099 -7.3 -3 3.2 9.2 10.6 1260

[0146] [Table8] Parameter R15BL at 1550 R10BL at 1550 R7.5BL at 1550 R15BL at 1625 R10BL at 1625 R7.5BL at 1625 (Units) (dB / 10 revolutions) (dB / revolution) (dB / revolution) (dB / 10 revolutions) (dB / revolution) (dB / revolution) Minimum value 0.001 0.013 0.090 0.007 0.048 0.224 Maximum value 0.150 0.32 1.53 0.64 0.84 2.97

[0147] Thus, it can be observed from the examples in Tables [Table 3] to [Table 14] and the ranges presented in Tables [Table 15] to [Table 18], that the radius and index parameters of the core and coating of the optical fiber according to the invention, make it possible to obtain a ZDW shifted towards higher wavelengths compared to the optical fibers of the prior art according to recommendations G,652 and G,657.

[0148] Indeed, standard fibers, according to recommendation G.657.A1, have a ZDW between 1300 and 1324 nm, while the optical fiber according to the invention has a ZDW between 1340 and 1359 nm, as illustrated in [Table 17]. Such a ZDW shift makes it possible to obtain an optical fiber optimized for use in the O and E bands.

[0149] Furthermore, the zero dispersion slope (ZDS) of the optical fibers according to the invention is predominantly less than 0.092 ps / nm²-km in Examples 1 to 94, unlike the attributes of G652 or G657. Thus, the optical fibers according to the invention do not conform to the chromatic dispersion attributes of G652 and G657, in particular for ZDW is completely different, and so is ZDS in most cases.

[0150] Furthermore, the present invention also makes it possible to obtain an optical fiber with an MFD, cable break, and bend losses similar to those of the G.652 and G.657 recommendations. More particularly, as illustrated by [Table 1] and [Table 18], the optical fibers according to the invention comply with the macro-bending requirements of G657A1 or G657A2,

[0151] Therefore, the present invention makes it possible to obtain a single-mode optical fiber similar to the standard optical fibers of the G.652 and G.657 recommendations, but optimized to operate with a higher wavelength in the O and E bands due to a higher ZDW which is obtained with specific radii (r0, rb r2, r3) and indices (An0, An2, An3) in the core 10 and the coating 20 of the optical fiber 1.

Claims

1.

2.

3. Claims Single-mode optical fiber including: a core (10) having a refractive index n, wherein the core includes a region in which the value of n decreases from a value n0 at a radius r0, to a value n2 at a radius ri; and a coating (20) having a refractive index n', said coating comprising: a first coating layer (21) in which the refractive index n' is equal to n2; and a second coating layer (22) in which the refractive index n' is equal to a value n3 less than n2; a third coating layer (23) in which the refractive index n' is equal to a value n4 greater than n3; in which the core radius ri is between 2.5 pm and 5.5 pm; and in which a refractive index difference An0 = n0-n4 is greater than 5.8 x 103; and in which a difference in refractive index An2 = n2 - n4 is between 1 x 103 and 2.5 x 103; and and in which a refractive index difference An3 = n3 - n4 is less than 0. A single-mode optical fiber according to claim 1, wherein the third cladding layer (23) is composed of silica. Single-mode optical fiber according to any one of the claims previous, in which the refractive index profile of the core and the cladding is defined by the following profile parameters: Ki = Vu - 5.85 x VOi K2 = V02 + 0.65 x Voi K3 = V03 - 5 x K2 where Voi is a surface integral of the soul; Vu is a volume integral of the soul; V02 is a surface integral of the first coating layer; V03 is a surface integral of the second coating layer; and in which said parameters respect the following inequalities: -59 < K! < -47 18 <K2<24 -133 < K3 <-118.

4. Single-mode optical fiber according to one of the preceding claims, in which the refractive index profile of the core is trapezoidal, with a ratio between 0 and 1, and preferably between 0.05 and 0.95, in which said ratio is equal to ro / rp

5. A single-mode optical fiber according to any preceding claim, wherein the refractive index or core profile has rounded edges.

6. A single-mode optical fiber according to any preceding claim, wherein the refractive index profile of the core has a depressed inner central region extending from the center of the core to radius rD, wherein rD is less than r0, and wherein the refractive index n of the core has a minimum value at the center of the core equal to n0D, wherein n0D is less than n0.

7. A single-mode optical fiber according to any preceding claim, wherein the region exhibiting a decrease in refractive index is obtained by gradually changing a concentration of at least two dopants.

8. Single-mode optical fiber according to the preceding claim, in which the at least two dopants are chosen from the following elements and / or molecules: - germanium oxide (GeO2); - fluorine (F); - phosphorus oxide (PXOY); - boron oxide (BXOY); - aluminum oxide (A12O3).

9. A single-mode optical fiber according to any preceding claim, wherein said optical fiber has a chromatic dispersion of between -9 and +3 ps / (nm.km) in the wavelength range of 1268 to 1375 nm.

10. A single-mode optical fiber according to any preceding claim, wherein said optical fiber has a field diameter mode (MFD) at a wavelength of 1310 nm which is between 8.6 and 9.2 pm and preferably equal to 9 pm.

11. A single-mode optical fiber according to any preceding claim, wherein said optical fiber has a cable cutoff wavelength between 1170 nm and 1260 nm.

12. A single-mode optical fiber according to any preceding claim, wherein said optical fiber has a zero-dispersion wavelength of between 1340 and 1360 nm.

13. A fiber optic transmission system wherein the same comprises at least one single-mode optical fiber according to any one of the preceding claims.

14. The fiber optic transmission system of claim 13, wherein said transmission system has a maximum transmitter dispersion penalty of 1.5 dB.

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