WO1999022258A1 - Fibre optique a dephasage dispersif - Google Patents
Fibre optique a dephasage dispersif Download PDFInfo
- Publication number
- WO1999022258A1 WO1999022258A1 PCT/JP1998/004857 JP9804857W WO9922258A1 WO 1999022258 A1 WO1999022258 A1 WO 1999022258A1 JP 9804857 W JP9804857 W JP 9804857W WO 9922258 A1 WO9922258 A1 WO 9922258A1
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- WIPO (PCT)
- Prior art keywords
- optical fiber
- dispersion
- refractive index
- core
- region
- Prior art date
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Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/036—Optical fibres with cladding with or without a coating core or cladding comprising multiple layers
- G02B6/03616—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference
- G02B6/03661—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference having 4 layers only
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/02004—Optical fibres with cladding with or without a coating characterised by the core effective area or mode field radius
- G02B6/02009—Large effective area or mode field radius, e.g. to reduce nonlinear effects in single mode fibres
- G02B6/02014—Effective area greater than 60 square microns in the C band, i.e. 1530-1565 nm
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/02214—Optical fibres with cladding with or without a coating tailored to obtain the desired dispersion, e.g. dispersion shifted, dispersion flattened
- G02B6/02219—Characterised by the wavelength dispersion properties in the silica low loss window around 1550 nm, i.e. S, C, L and U bands from 1460-1675 nm
- G02B6/02228—Dispersion flattened fibres, i.e. having a low dispersion variation over an extended wavelength range
- G02B6/02238—Low dispersion slope fibres
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/028—Optical fibres with cladding with or without a coating with core or cladding having graded refractive index
- G02B6/0281—Graded index region forming part of the central core segment, e.g. alpha profile, triangular, trapezoidal core
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/028—Optical fibres with cladding with or without a coating with core or cladding having graded refractive index
- G02B6/0286—Combination of graded index in the central core segment and a graded index layer external to the central core segment
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/036—Optical fibres with cladding with or without a coating core or cladding comprising multiple layers
- G02B6/03605—Highest refractive index not on central axis
- G02B6/03611—Highest index adjacent to central axis region, e.g. annular core, coaxial ring, centreline depression affecting waveguiding
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/036—Optical fibres with cladding with or without a coating core or cladding comprising multiple layers
- G02B6/03616—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference
- G02B6/03622—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference having 2 layers only
- G02B6/03627—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference having 2 layers only arranged - +
Definitions
- the present invention relates to a single mode optical fiber used as a transmission line in optical communication and the like, and more particularly to a dispersion-shifted optical fiber suitable for wavelength division multiplexing (wavelength division multiplexing) transmission.
- the core region surrounded by the cladding region has a ring-shaped core structure including an inner core and an outer core provided on the outer periphery of the inner core.
- the refractive index of the outer core is set higher than that of the inner core.
- the nonlinear optical effect is caused by nonlinear phenomena such as four-wave mixing (FWM), self-phase modulation (SPM), and cross-phase modulation (XPM).
- FWM four-wave mixing
- SPM self-phase modulation
- XPM cross-phase modulation
- the present invention has been made to solve such a problem at the time of drawing an optical fiber, and has a structure for effectively eliminating a factor of characteristic deterioration in a manufacturing stage, and is suitable for wavelength multiplex transmission. It is intended to provide a dispersion-shifted optical fiber.
- a dispersion-shifted optical fiber is a dispersion-shifted optical fiber including a core region extending along a predetermined axis and a cladding region provided on an outer periphery of the core region.
- the added impurities and the amount of the added impurities are adjusted.
- the core region includes an inner core in which the concentration distribution of a refractive index lowering agent such as fluorine (F) is adjusted so that a refractive index is higher in a peripheral portion than in a central portion; provided on the outer periphery of, and an outer core comprising a refractive index increasing agent such as germanium oxide (G e 0 2).
- the outer core is an inner portion where the refractive index increases from the center to the periphery of the dispersion-shifted optical fiber, and a region provided between the inner portion and the cladding region. Shift from the center of the shift optical fiber At least an outer portion whose refractive index decreases toward the side is provided.
- a ratio of a change amount of a relative refractive index difference to a radius of the outer portion is 1.0% / 1m or less. It is characterized by.
- the inner portion of the outer core means a portion in contact with the inner core, and the outer portion means a portion in contact with the cladding region. Therefore, the inner part and the outer part may be composed of one or more parts having different relative refractive index differences between the cladding region and the reference region, and an intermediate part is provided between the inner part and the outer part. It is also possible. Further, in each portion of the outer core, the added refractive index increasing agent may be different.
- At least the inner portion of the outer core contains a first additive for increasing the refractive index, and at least the outer portion of the outer core is melted when the outer core is melted. It may be configured to include a second additive that lowers the viscosity of the composition.
- the outer core may include an inner portion and an outer portion each including a plurality of portions including at least one of the first additive and the second additive.
- a refractive index profile that changes stepwise along the radial direction in the outer core can be realized. Even with such a structure, the occurrence of structural irregularities and glass defects near the interface between the regions during fiber drawing is suppressed, and the outer core The rapid thermal expansion in the above is suppressed.
- the effective area A eff is given by the following equation (1), as shown in JP-A-8-248251.
- E is the electric field associated with the propagating light
- r is the radial distance from the center of the core region.
- the refractive index profile is represented by a relative refractive index difference Arii given by the following equation (2).
- n cd is the average refractive index of the reference region (S i 0 2 ) in the cladding region
- rii is the average refractive index of each part i that constitutes the core region. It is. Therefore, the relative refractive index difference ⁇ ni is expressed based on the average refractive index n cd of the reference region in the cladding region. In this specification, the relative refractive index difference is expressed in percentage, and a region having a negative relative refractive index difference indicates a region having a lower refractive index than the reference region.
- the difference between the maximum value of the relative refractive index difference in the outer core and the minimum value in the inner core is , 1.0% or more.
- the maximum refractive index in the outer core is preferably the maximum refractive index in the dispersion-shifted optical fiber
- the minimum refractive index in the inner core is preferably the minimum refractive index in the dispersion-shifted optical fiber.
- the first additive contained in the desired portion of the outer core contains at least germanium oxide, and the second additive contains at least phosphorus. Then, the addition amount of the second additive is adjusted so as to decrease from the center to the periphery of the dispersion-shifted optical fiber.
- the cladding region is provided on the outer periphery of the outer core and has an inner cladding having a predetermined refractive index; A depressed cladding structure with an outer cladding having a higher refractive index than the cladding may be used. When this cladding structure is adopted, the outer cladding serves as a reference region for the cladding region.
- FIG. 1A is a diagram showing a cross-sectional structure of a first embodiment of the dispersion-shifted optical fiber according to the present invention
- FIG. 1B is a refractive index profile of the dispersion-shifted optical fiber of the first embodiment shown in FIG. 1A. It is.
- FIG. 2A is a diagram showing a cross-sectional structure of a second embodiment of the dispersion-shifted optical fiber according to the present invention
- FIG. 2B is a refractive index profile of the dispersion-shifted optical fiber of the second embodiment shown in FIG. 2A. It is.
- FIG. 3A is a diagram showing a cross-sectional structure of a third embodiment of the dispersion shifted optical fiber according to the present invention
- FIG. 3B is a refractive index profile of the dispersion shifted optical fiber of the third embodiment shown in FIG. 3A. It is.
- FIG. 4A is a diagram showing a cross-sectional structure of a fourth embodiment of the dispersion-shifted optical fiber according to the present invention
- FIG. 4B is a refractive index profile of the dispersion-shifted optical fiber of the fourth embodiment shown in FIG. 4A. It is. BEST MODE FOR CARRYING OUT THE INVENTION
- FIGS. 1A to 4B embodiments of the dispersion-shifted optical fiber according to the present invention will be described with reference to FIGS. 1A to 4B.
- the same or equivalent elements are denoted by the same reference numerals.
- FIG. 1A shows a cross-sectional structure of a first embodiment of the dispersion-shifted optical fiber according to the present invention.
- the dispersion-shifted optical fiber according to the first embodiment is a single fiber that guides signal light in the 1.55 ⁇ m wavelength band whose center wavelength is in the range of about 150 nm to 160 nm. Mode optical fiber.
- the dispersion-shifted light flux 100 is provided on a core region 110 extending along a predetermined axis and on the outer periphery of the core region 110.
- the core region 1 110 has an inner core 1 1 1 having an outer diameter a 1 (2 jam) and an outer core 1 1 2 having an outer diameter b 1 (10 ⁇ m). Is provided.
- Fluorine as a refractive index lowering agent is added to the inner core 111, and the amount of the fluorine gradually decreases from the center 0 to the periphery of the dispersion-shifted optical fiber 100.
- Ge 2 as a refractive index increasing agent is added to the outer core 112.
- the addition amount of Ge 2 in the inner portion 1 2 a of the outer core 1 1 2 It gradually increases from the center 0 of the optical fiber '100 to the periphery.
- FIG. 1B is a refractive index profile of the dispersion-shifted optical fiber 100 of the first embodiment shown in FIG. 1A, and corresponds to a line L1 passing through the center 0 of the dispersion-shifted optical fiber 100. It is represented by the relative refractive index difference of each part along.
- the relative refractive index difference of each glass region is given by the above equation (2), using the cladding region 120 as a reference region.
- the minimum value ⁇ of the relative refractive index difference with respect to the cladding region 120 is -The amount of fluorine added is adjusted to 0.6%.
- the maximum value of the relative refractive index difference ⁇ 2 with respect to the cladding region 1 20 is ⁇ 2 There 1. so as to be 2%, GeO 2 added amount is adjusted.
- the relative refractive index difference 1 ⁇ (r) of the inner portion 1 12 & of the outer core 1 12 is substantially constant from the inner core 11 1 to the cladding region 120 at a constant rate of change of 0.1. It changes at 6% / ⁇ m.
- the relative refractive index difference Ar (r) of the outer portion 1 12b of the outer core 1 12 changes at a substantially constant rate of change of 0.6% / ⁇ m from the inner core 1 11 to the cladding region 120. are doing.
- the relative refractive index difference ⁇ is the minimum value in the entire optical fiber
- the relative refractive index difference ⁇ 2 is the maximum value in the entire optical fiber.
- the difference between these relative refractive index differences ( ⁇ is designed to be 1.0% or more.
- the amounts of GeO 2 and fluorine added to the base material are adjusted.
- the base material is formed in advance so as to have the structure shown in FIG. 1A. Then, a manufacturing method is adopted in which a dispersion-shifted optical fino 100 having a refractive index profile 150 shown in FIG. 1B is formed by drawing the base material.
- dispersion-shifted optical fiber 100 it was confirmed that the transmission loss for the signal light having the wavelength of 155 Onm was extremely low, 0.22 dB / km. Further, as characteristics at a wavelength of 155 onm, dispersion value is 2. 5 ps / nm / km, a dispersion slope 0. 085 ps / nm 2 / km , effective area A ef f is 80 ⁇ m 2, and the wavelength multiplexing Evaluation results suitable for transmission were obtained.
- the interface of the outer core 112 (the interface between the inner core 111 and the outer core 112 and the cladding region 120) is formed. And at least the interface between the outer core and the outer core), the sharp change in stress can be suppressed. As a result, the occurrence of structural irregularities and glass defects near the interface of the outer core 112 was effectively suppressed.
- FIG. 2A is a diagram showing a cross-sectional structure of a second embodiment of the dispersion-shifted optical fiber according to the present invention.
- the dispersion-shifted optical fiber according to the second embodiment has a single wavelength of 1.55 ⁇ m and has a center wavelength within a range of about 150 nm to 160 nm. Mode optical fiber.
- the dispersion-shifted optical fiber 200 includes a core region 210 extending along a predetermined axis and a cladding provided on the outer periphery of the core region 210.
- the core area 210 includes an inner core 211 having an outer diameter a2 (2 ⁇ m) and an outer core 212 having an outer diameter b2 (10 ⁇ m). I have.
- Fluorine as a refractive index lowering agent is added to the inner core 211, and the amount of this fluorine gradually decreases from the center 02 of the dispersion-shifted optical fiber 200 toward the periphery. ing.
- the G e O 2 as the refractive index increasing agent is added to the outer core 2 1 2.
- G e 0 2 amount in the inner part 2 1 2 a of the outer core 2 1 2 The dispersion-shifted It has increased gradually toward the periphery from the center 0 2 of the optical fiber 2 0 0.
- the second embodiment is characterized in that the inner core 211 and the outer core 211 are constituted by a plurality of portions each having a different refractive index to realize a step-like refractive index profile.
- Figure 2 B is a refractive index profile of the dispersion-shifted optical fiber 200 of the second embodiment shown in FIG. 2 A, of each portion along the line L 2 passing through the center 0 2 of the dispersion shift optical fiber 200 It is represented by a relative refractive index difference.
- Each glass region relative refractive index difference is given by the above equation (2) using the cladding region 220 as a reference region.
- the minimum value ⁇ ⁇ of the relative refractive index difference with respect to the cladding region 220 is —0.6 %.
- the amount of fluorine added is adjusted so that In the outer core 2 1 2 outer diameter b 2 (1 O jm), so that the maximum value .DELTA..eta 2 relative refractive index difference with respect to clad region 220 is 2% 1., Ge 0 2 amount is adjusted .
- the inner portion 212a of the outer core 212 has a plurality of different refractive indexes such that the relative refractive index difference ⁇ ⁇ (r) changes stepwise along the radial direction.
- the rate of change in the radial direction is 0.5% / m.
- the outer portion 211b of the outer core 212 also includes a plurality of portions having different refractive indices so that the relative refractive index difference Arii (r) changes stepwise in the radial direction.
- the rate of change in the radial direction of the outer portion 2 12 b is ⁇ 0.3% / ⁇ m.
- the relative refractive index difference ⁇ ⁇ is the minimum value in the entire optical fiber
- the relative refractive index difference 2 n 2 is the maximum value in the entire optical fiber. It is designed so that the difference between these relative refractive index differences ( ⁇ 2 — ⁇ ⁇ ) is 1.0% or more. With this configuration, a dispersion shifted optical fiber having a smaller dispersion slope and a larger effective area can be obtained.
- the dispersion-shifted optical fiber 200 having the structure shown in Fig. 2 ⁇
- the amounts of GeO 2 and fluorine added to the base material are adjusted.
- the base material is molded in advance so as to have a structure shown in FIG. 2A after the drawing process.
- a manufacturing method is adopted in which a dispersion-shifted optical fiber 200 having a refractive index profile 250 shown in FIG. 2B is formed by drawing the base material.
- the transmission loss for the signal light having the wavelength of 1550 nm was extremely low, 0.22 dB / km.
- the dispersion value is 2. 0 ps / nm / km, a dispersion slope 0. 09 0 ps / nm 2 / km, the effective area A ef f 80 ⁇ m 2, and the Evaluation results suitable for wavelength division multiplexing transmission were obtained.
- the refractive index profile of the outer core 212 into a step shape as described above, it becomes easy to automatically control the manufacturing conditions in the manufacturing process, and the rate of change of the relative refractive index difference is optimally controlled with high precision. Can be. Therefore, a dispersion-shifted optical fiber that is homogeneous and has good reproducibility can be obtained.
- FIG. 3A is a diagram showing a cross-sectional structure of a third embodiment of the dispersion-shifted optical fiber according to the present invention.
- the dispersion-shifted optical fiber according to the third embodiment is a single-mode optical fiber that guides signal light in the 1.55 m wavelength band whose center wavelength is in the range of about 1500 nm to 160 O nm. is there.
- the dispersion-shifted optical finos 300 include a core region 310 extending along a predetermined axis and a cladding region 320 provided on the outer periphery of the core region 310.
- the core region 310 includes an inner core 311 having an outer diameter a3 (2 m) and an outer core 312 having an outer diameter c3 (10j).
- the inner core 3 11 is adjacent to the inner core 3 11 in the outer core 3 12.
- An intermediate portion 312b having an outer diameter b3 (8 ⁇ m) is provided between the side portion 312a and the outer portion 312c adjacent to the cladding region 320, and each portion of the outer core 312 is provided.
- GeO 2 and phosphorus as refractive index increasing agent is added to the desired portion each of the outer core 312.
- the Ge 0 2 is added to the inner part 3 12 a of the outer core 3 12, the GeO 2 added amounts, the The dispersion shift optical fiber 300 gradually increases from the center ⁇ 3 toward the periphery.
- phosphorus is added to the outer portion 312c of the outer core 312 in order to reduce the viscosity difference near the interface between the cladding region 320 and the outer core 312. gradually decreases from the center 0 3 of the shifted optical fiber 300 toward the periphery.
- the middle portion 3 12 b of the outer diameter b (8 m) provided between the inner portion 312 a and the outer portion 312 c is not affected by a defect near the interface of the outer core 3 12. since, Ge 0 2 is added substantially uniformly.
- FIG. 3 B is the refractive index profile of the dispersion shifted optical fiber 300 of the third embodiment shown in FIG. 3 A, each along the line L 3 passing through the center 0 3 of the dispersion shifted optical fiber 300 It is represented by the relative refractive index difference of the site.
- the relative refractive index difference between the respective glass regions is given by the above equation (2) using the cladding region 320 as a reference region.
- the minimum value of the relative refractive index difference Ar with respect to the cladding region 320 is —0.6%.
- the amount of fluorine added is adjusted so that In the outer core 3 12 having the outer diameter c 3 (10 im), Ge0 2 in the inner portion 3 12 a is added so that the relative refractive index difference Ani (r) increases from the inner core 31 1 toward the cladding region 320.
- the volume has been adjusted.
- Ge 0 2 is It is added substantially uniformly so that the relative refractive index difference ⁇ 2 with respect to the region 320 becomes 1.0%.
- phosphorus is added to the outer portion 3 12 c of the outer diameter c 3 (10 ⁇ m), and the amount of phosphorus gradually decreases from the inner core 3 11 to the cladding region 320.
- the relative refractive index difference ⁇ is the minimum value in the entire optical fiber
- the relative refractive index difference ⁇ 2 is the maximum value in the entire optical fiber.
- the difference ( ⁇ 2 — ⁇ ⁇ ) between the relative refractive index differences is designed to be 1.0% or more.
- the amount of GeO2, fluorine and phosphorus added to the base material during the process of manufacturing the base material before the drawing processing is required. Is adjusted, and the base material is molded in advance so that the structure shown in FIG. 3A is obtained after the drawing process. Then, a manufacturing method is adopted in which the base material is drawn to form a dispersion-shifted optical fiber 300 having a refractive index profile 350 shown in FIG. 3B.
- the transmission loss for the signal light having the wavelength of 1550 nm was extremely low, 0.22 dB / km.
- the dispersion value is 2.5 ps / nm / km
- the dispersion slope is 0.9 ⁇ 90 ps / nm 2 / km
- the effective area A eff is 80 / m 2 . Evaluation results suitable for wavelength division multiplexing transmission were obtained.
- FIG. 4A is a diagram showing a sectional structure of a fourth embodiment of the dispersion-shifted optical fiber according to the present invention.
- the dispersion-shifted optical fiber according to the fourth embodiment is a single fiber that guides a signal light in a 1.55 ⁇ m wavelength band whose center wavelength is in a range of about 150 O nm to 160 O nm. Mode optical fiber.
- the dispersion-shifted light Fino 100 is provided on the outer periphery of the core region 410 extending along a predetermined axis and the core region 410.
- a cladding region 4 20 is provided, and the core region 4 10 further comprises an inner core 4 1 1 having an outer diameter a 4 (2.6 jum) and an outer core 4 1 2 having an outer diameter c 4 (9.8 ⁇ m). It has.
- the cladding region 420 is formed of an inner cladding 421 having an outer diameter d4 (13.9 urn) and an outer cladding 422 provided on the outer periphery of the inner cladding 421. It has a pressurized cladding structure.
- the above inner core 4 1 1 are added fluorine as a refractive index lowering agent, the addition amount of the fluorine is substantially constant near the center ⁇ 4 of the dispersion shifted optical fiber 4 0 0, toward the periphery And gradually decreasing.
- the G e 0 2 as the refractive index increasing agent is added to the outer core 4 1 2.
- the amount of Ge 0 2 added to the inner portion 4 12 a of the outer core 4 12 It gradually increases from the center ⁇ 4 of the optical fiber 400 toward the periphery.
- FIG. 4 B is a refractive index profile of the dispersion-shifted Bok optical fiber 4 0 0 of the fourth embodiment shown in FIG. 4 A, passing through the center 0 4 of the dispersion shifted optical fiber 4 0 0 It is represented by the relative refractive index difference of each part along the line L4.
- the relative refractive index difference between the respective glass regions is given by the above equation (2) using the outer cladding 422 of the cladding region 420 as a reference region.
- the dispersion-shifted optical fiber 400 is designed so that the difference in viscosity near the interface between the respective glass regions is reduced.
- the minimum value ⁇ of the relative refractive index difference — of the inner core 411 of the outer diameter a4 (2.6 JLL m) with respect to the outer clad 422 becomes ⁇ 0.5%.
- the amount of fluorine added is adjusted so that In the outer core 412 having an outer diameter c 4 (9. Sum), so that the maximum value .DELTA..eta 2 relative refractive index difference with respect to the outer clad 422 is 0% 1.
- Ge0 2 added amount is adjusted.
- the relative refractive index difference with the outer clad 422 - 0.2% in so as, GeO 2 is added substantially uniformly.
- the relative refractive index difference ⁇ (r) of the inner portion 412a of the outer core 412 is substantially constant from the inner core 411 toward the outer clad 422 at a rate of change of 0.8% / ⁇ M is changing.
- the relative refractive index difference ⁇ (r) of the outer portion 412b of the outer core 412 changes at a substantially constant rate of change of 0.7% // m from the inner core 411 to the outer cladding 422.
- the relative refractive index difference ⁇ n is the minimum value in the entire optical fiber
- the relative refractive index difference 2 n 2 is the maximum value in the entire optical fiber.
- the difference between these relative refractive index differences ( ⁇ 2 — ⁇ is designed to be 1.0% or more.
- the amounts of GeO 2 and fluorine added to the base material are adjusted.
- the base material is formed in advance so as to have a structure shown in FIG. 4A after the drawing process.
- the base material is drawn to form a dispersion-shifted optical fiber 400 having a refractive index profile 450 shown in FIG. 4B.
- the manufacturing method of forming is adopted.
- the transmission loss with respect to the signal light having a wavelength of 1550 nm was as low as 0.21 dB / km.
- the dispersion value was 2.5 ps / nm / km and the effective area was 81 m 2 , and evaluation results suitable for wavelength division multiplexing transmission were obtained.
- a depressed cladding structure is adopted as the structure of the cladding region 420, but this depressed cladding structure is the same as any of the first to third embodiments. It is also possible to apply.
- the present invention while reducing the refractive index of the inner core with respect to the reference region of the cladding region, increasing the refractive index of the outer core with respect to the reference region of the cladding region, By setting the distribution of the relative refractive index difference of the core to a predetermined rate of change, the viscosity difference near the interface of the outer core can be reduced during the drawing process, and a rapid change in stress can be suppressed. This has the effect of effectively suppressing the occurrence of structural irregularities and glass defects near the interface of the outer core. Furthermore, by reducing the difference in thermal expansion between the regions, the occurrence of problems such as cracking of the optical fiber preform in the optical fin preform manufacturing process is suppressed.
- the outer portion adjacent to the cladding region is provided.
- an impurity that lowers the viscosity of the outer core during melting is added, and the amount of the impurity added is distributed so as to reduce the change in viscosity near the interface of the outer core. This has the effect of reducing the occurrence of structural irregularities and glass defects, and of suppressing rapid thermal expansion in the outer core.
- the occurrence of structural defects such as structural irregularities and glass defects near the interface of the outer core is effectively suppressed, so that non-linear phenomena are unlikely to occur and wavelength multiplexing transmission is achieved.
- a suitable dispersion-shifted optical fiber can be obtained.
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Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP98950408A EP1028329A4 (en) | 1997-10-29 | 1998-10-27 | OPTICAL FIBER WITH DISPERSIVE PHASE |
AU96487/98A AU9648798A (en) | 1997-10-29 | 1998-10-27 | Dispersion-shifted optical fiber |
US09/560,399 US6360046B1 (en) | 1997-10-29 | 2000-04-28 | Dispersion-shifted optical fiber |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP9/297315 | 1997-10-29 | ||
JP29731597 | 1997-10-29 |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/560,399 Continuation-In-Part US6360046B1 (en) | 1997-10-29 | 2000-04-28 | Dispersion-shifted optical fiber |
Publications (1)
Publication Number | Publication Date |
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WO1999022258A1 true WO1999022258A1 (fr) | 1999-05-06 |
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ID=17844927
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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PCT/JP1998/004857 WO1999022258A1 (fr) | 1997-10-29 | 1998-10-27 | Fibre optique a dephasage dispersif |
Country Status (5)
Country | Link |
---|---|
US (1) | US6360046B1 (ja) |
EP (1) | EP1028329A4 (ja) |
AU (1) | AU9648798A (ja) |
TW (1) | TW381185B (ja) |
WO (1) | WO1999022258A1 (ja) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
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JP2003207673A (ja) * | 2002-01-14 | 2003-07-25 | Alcatel | 複雑な屈折率プロファイルを有する光ファイバー |
Families Citing this family (11)
Publication number | Priority date | Publication date | Assignee | Title |
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CA2347272A1 (en) * | 1999-08-20 | 2001-03-01 | The Furukawa Electric Co., Ltd. | Optical fiber and optical transmission line |
US6603914B2 (en) | 2001-02-07 | 2003-08-05 | Fitel Usa Corp. | Dispersion compensating fiber with reduced splice loss and methods for making same |
US6490398B2 (en) * | 2001-02-21 | 2002-12-03 | Fitel Usa Corp. | Dispersion-compensating fiber having a high figure of merit |
EP1343032A1 (en) * | 2002-03-06 | 2003-09-10 | FITEL USA CORPORATION (a Delaware Corporation) | Dispersion compensating fiber with reduced splice loss and methods for making same |
GB2403816A (en) | 2003-07-11 | 2005-01-12 | Fujitsu Ltd | Optical device with radial discontinuities in the refractive index |
FR2893149B1 (fr) | 2005-11-10 | 2008-01-11 | Draka Comteq France | Fibre optique monomode. |
FR2899693B1 (fr) * | 2006-04-10 | 2008-08-22 | Draka Comteq France | Fibre optique monomode. |
US7450807B2 (en) | 2006-08-31 | 2008-11-11 | Corning Incorporated | Low bend loss optical fiber with deep depressed ring |
CN102099711B (zh) | 2007-11-09 | 2014-05-14 | 德雷卡通信技术公司 | 抗微弯光纤 |
FR2930997B1 (fr) | 2008-05-06 | 2010-08-13 | Draka Comteq France Sa | Fibre optique monomode |
JP6335949B2 (ja) * | 2016-02-12 | 2018-05-30 | 株式会社フジクラ | マルチコアファイバ |
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JPS5238941A (en) * | 1975-09-22 | 1977-03-25 | Sumitomo Electric Ind Ltd | Optical fiber |
JPS61262708A (ja) * | 1985-05-17 | 1986-11-20 | Sumitomo Electric Ind Ltd | 1.5ミクロン帯用シングルモ−ド光フアイバ |
JPS63208005A (ja) * | 1987-02-25 | 1988-08-29 | Sumitomo Electric Ind Ltd | 光フアイバ |
JPH0344604A (ja) * | 1989-07-13 | 1991-02-26 | Fujikura Ltd | 1.55μm分散シフトファイバ |
JPH0933744A (ja) * | 1995-07-07 | 1997-02-07 | Alcatel Submarcom | 大きな有効モード表面積を有する低分散単一モード光導波路 |
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GB2046239A (en) * | 1979-04-11 | 1980-11-12 | Post Office | Optical fibres |
JPS62165608A (ja) * | 1986-01-17 | 1987-07-22 | Fujitsu Ltd | シングルモ−ド光フアイバ |
FR2724234B1 (fr) * | 1994-09-05 | 1997-01-03 | Alcatel Fibres Optiques | Fibre optique monomode a dispersion decalee |
US5613027A (en) | 1994-10-17 | 1997-03-18 | Corning Incorporated | Dispersion shifted optical waveguide fiber |
US5835655A (en) | 1995-01-26 | 1998-11-10 | Corning Incorporated | Large effective area waveguide fiber |
DE69630426T2 (de) * | 1995-08-31 | 2004-08-19 | Sumitomo Electric Industries, Ltd. | Dispersionskompensierende Faser und Verfahren zu ihrer Herstellung |
AU715435B2 (en) * | 1996-02-12 | 2000-02-03 | Corning Incorporated | Single mode optical waveguide having large effective area |
US5684909A (en) * | 1996-02-23 | 1997-11-04 | Corning Inc | Large effective area single mode optical waveguide |
AU734749B2 (en) * | 1997-08-28 | 2001-06-21 | Sumitomo Electric Industries, Ltd. | Dispersion-shifted fiber |
WO1999018461A1 (fr) * | 1997-10-02 | 1999-04-15 | Sumitomo Electric Industries, Ltd. | Fibre optique a decalage et dispersion |
-
1998
- 1998-10-27 WO PCT/JP1998/004857 patent/WO1999022258A1/ja active Application Filing
- 1998-10-27 EP EP98950408A patent/EP1028329A4/en not_active Ceased
- 1998-10-27 AU AU96487/98A patent/AU9648798A/en not_active Abandoned
- 1998-10-28 TW TW087117848A patent/TW381185B/zh not_active IP Right Cessation
-
2000
- 2000-04-28 US US09/560,399 patent/US6360046B1/en not_active Expired - Fee Related
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
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JPS5238941A (en) * | 1975-09-22 | 1977-03-25 | Sumitomo Electric Ind Ltd | Optical fiber |
JPS61262708A (ja) * | 1985-05-17 | 1986-11-20 | Sumitomo Electric Ind Ltd | 1.5ミクロン帯用シングルモ−ド光フアイバ |
JPS63208005A (ja) * | 1987-02-25 | 1988-08-29 | Sumitomo Electric Ind Ltd | 光フアイバ |
JPH0344604A (ja) * | 1989-07-13 | 1991-02-26 | Fujikura Ltd | 1.55μm分散シフトファイバ |
JPH0933744A (ja) * | 1995-07-07 | 1997-02-07 | Alcatel Submarcom | 大きな有効モード表面積を有する低分散単一モード光導波路 |
JPH09159856A (ja) * | 1995-10-04 | 1997-06-20 | Sumitomo Electric Ind Ltd | シングルモード光ファイバ及びその製造方法 |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003207673A (ja) * | 2002-01-14 | 2003-07-25 | Alcatel | 複雑な屈折率プロファイルを有する光ファイバー |
JP4493917B2 (ja) * | 2002-01-14 | 2010-06-30 | アルカテル−ルーセント | 複雑な屈折率プロファイルを有する光ファイバー |
Also Published As
Publication number | Publication date |
---|---|
TW381185B (en) | 2000-02-01 |
EP1028329A1 (en) | 2000-08-16 |
AU9648798A (en) | 1999-05-17 |
US6360046B1 (en) | 2002-03-19 |
EP1028329A4 (en) | 2005-04-27 |
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