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公开(公告)号：JPH10300965A
公开(公告)日：1998-11-13
申请号：JP6564498
申请日：1998-03-16
Applicant: LUCENT TECHNOLOGIES INC
Inventor： VENGSARKAR ASHISH MADHUKAR , WAGENER JEFFERSON LYNN
Abstract: PROBLEM TO BE SOLVED: To provide a dispersed compensation type (DC) optical fiber which is scarcely exposed to unexpected fluctuation of optical fiber characteristics, by selecting a mode so that a nominal dispersion is everything in higher-order modes. SOLUTION: An inner clad layer 12 is formed in contact with periphery of a core 11, and further, refractive index ring 13 and outer clad layer 14 are formed. The core 11 has a step profile, and Δnom =1.8%. This step profile of the core 11 is selected so as to give dispersion. A refractive index of the refractive index ring 13 is n2 ,nom , and it is selected so as to be (n2 ,nom -n1 ,nom )/n2 ,nom >0.1%, typically 0.4%, and light is refracted so that clad layers 12, 14 have a refraction index of n2 ,nom and have a same refraction index. DC fiber is mainly used in LP02 mode for dispersed compensation, because LP02 mode has a high dispersion in the neighborhood of cutoff, and has preferably a negative value not larger than -200 ps/nm.km.
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公开(公告)号：JPH1184152A
公开(公告)日：1999-03-26
申请号：JP18600498
申请日：1998-07-01
Applicant: LUCENT TECHNOLOGIES INC
Abstract: PROBLEM TO BE SOLVED: To write Bragg diffraction gratings into an optical fiber. SOLUTION: This method includes a process for manufacturing the Bragg reflection diffraction gratings using a phase mask and an amplitude mask device for manufacture of a Bragg reflector. The Bragg reflection diffraction gratings have the periods larger than the periods of the conventional short period diffraction gratings but much smaller than the periods of the conventional long-period diffraction gratings. This short-period Bragg reflection diffraction gratings have periods in a range of, for example, 1 to 10 μm. The method of manufacture includes the arrangement of the amplitude mask having internally formed suitable slits on a photosensitive waveguide to be manufactured, then irradiation of the waveguide through the slits and the consequent introduction of the periodic patterns of refractive index fluctuations which are the characteristic of the Bragg reflector by light. The short-period Bragg diffraction gratings generated by this amplitude mask are the reflection diffraction gratings having the reflection characteristics attaining nearly 99.99%. The reflective diffraction gratings manufactured according to this method are advantageous in applications, such as adding and decreasing of channels into a wavelength division multiplex system and the detection of the stabilization and structural imperfectness of a laser.
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公开(公告)号：JPH10107345A
公开(公告)日：1998-04-24
申请号：JP24365397
申请日：1997-09-09
Applicant: LUCENT TECHNOLOGIES INC
Inventor： DIGIOVANNI DAVID JOHN , VENGSARKAR ASHISH MADHUKAR
Abstract: PROBLEM TO BE SOLVED: To reduce the length of a device by allowing the core of an optical fiber, to have an effective mode diameter in the fundamental waveguide space mode of a laser wavelength and to have the diameter of the distribution region of a rare earth dopant, and then increasing the diameter of the distribution region as compared with the effective mode diameter of the distribution region. SOLUTION: In an optical fiber 10, an inner clad layer 13 and an outer clad layer 11 are formed around a core 12. Doping by a rare earth element is performed nearly constantly to the core 12 and the inner clad layer 13, while a dopnat for increasing a refractive index is performed further to the core 12. The diameter and the reflective index of the core 12 are selected, so that the optical fiber 10 is a single-mode fiber at a laser wavelength and has the effective mode diameter of a unique fundamental space mode. When the outer diameter of the inner clad layer 13 is set to the diameter of the distribution region of a rare earth element dopant, the diameter of the distribution region of the rare earth element dopant is made to be longer than the diameter of the effective mode.
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公开(公告)号：JPH10104460A
公开(公告)日：1998-04-24
申请号：JP24845397
申请日：1997-09-12
Applicant: LUCENT TECHNOLOGIES INC
Inventor： STRASSER THOMAS A , VENGSARKAR ASHISH MADHUKAR , WALKER KENNETH LEE
Abstract: PROBLEM TO BE SOLVED: To obtain a relatively low-cost, reliable, and low-loss waveguide device which has a passive addition/removal multiplexing function, etc., by providing a specific mode discriminating coupler(MDC) and a reflection mode coupling means. SOLUTION: This system has a device group consisting of an MDC 10 and the reflection mode coupling means arranged between a radiation source and a use means. The MDC 10 is a 4-port (14 to 17) coupler having a 1st multi-mode optical waveguide optical waveguide 12 which is coupled with a 2nd multi-mode optical waveguide 12 by evanescent coupling and is different from it. The evanescent field coupling propagates electromagnetic radiation in basic space mode of wavelength λi on the optical waveguides 1 and 12 through the MDC 10 and couples electromagnetic radiation in high-order space mode from one of the optical waveguides 11 and 12 to the other. The reflection mode coupling means consists of a reflection mode coupling grating which has such a blaze refractive index grating that the pitch Λ is less than 1μm and the blaze angle θ larger 3 deg. to the length of the multi-mode optical waveguide.
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公开(公告)号：JP2000066120A
公开(公告)日：2000-03-03
申请号：JP32117398
申请日：1998-11-12
Applicant: LUCENT TECHNOLOGIES INC
Inventor： ABRAMOV ANATOLI A , HALE ARTURO , MOCK JOEL LESLIE , STRASSER THOMAS A , VENGSARKAR ASHISH MADHUKAR
Abstract: PROBLEM TO BE SOLVED: To obtain a method capable of monitoring a multiple wavelength optical system without using costly elements, such as detector arrays and an apparatus therefor. SOLUTION: The physical parameters of the intra-fiber gratings for coupling the light used in the wavelength division multiplex(WDM) optical fiber system between the spatially different mode are scanned, i.e., changed. The space modes are separated by using a mode discrimination device(MDD) 47 and the spectral components separated by the conventional or other suitable detectors 48 are monitored, i.e., detected. The peak wavelength of the coupling the two different modes to each other is changed and the coupling in the fiber optical system is controlled by scanning the intra-fiber gratings. This system uses the long- period gratings for coupling the spatially different modes for propagating the light in the two same direction to each other or the short-period gratings for coupling the mode for propagating the light in a forward direction and the mode for propagating the light in the opposite direction spatially different therefrom to each other.
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Patent Agency Ranking
公开(公告)号：JPH11344620A
公开(公告)日：1999-12-14
申请号：JP9460399
申请日：1999-04-01
Applicant: LUCENT TECHNOLOGIES INC
IPC: G02B6/00 , G02B6/02 , G02B6/12 , G02B6/34 , G02F1/313 , H01S3/067 , H04B10/02 , H04B10/18 , G02B6/10
Abstract: PROBLEM TO BE SOLVED: To obtain a long period grating having a wide band width by adopting a constitution in which the inclination of the functions of the intervals of perturbations changes code in the region of an operation wavelength. SOLUTION: The grating comprises an optical fiber 10 for transmitting light in a guided (restrained) mode. The fiber 10 has a core 11 and a clad 12 having the refractive index lower than the refractive index thereof. The core 11 includes the long period grating 13 consisting of the plural refractive index perturbations 14 of width of W arranged apart periodic distances (intervals). The wide band long period grating varies in the relation between a wavelength λo and a grating period Λ from the conventional long period gratings. Namely, the grating consists of the plural refractive index perturbations parted by the distance larger than 10λ. The device exhibits the peak coupling wavelength λp changing as the function of the interval Λ of its perturbations and the dΛ/dλp of the function thereof changes the code in the region of the operation wavelength λas an improvement point. The wide band long period grating is so designed as to exhibit an inflection point where dΛ/l≈0 is attained at a concern wavelength.
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公开(公告)号：JPH11202113A
公开(公告)日：1999-07-30
申请号：JP29586598
申请日：1998-10-16
Applicant: LUCENT TECHNOLOGIES INC
Inventor： ABRAMOV ANATOLI A , HALE ARTURO , VENGSARKAR ASHISH MADHUKAR
Abstract: PROBLEM TO BE SOLVED: To minimize the temperature reactivity of the long-cycle diffraction grating device. SOLUTION: This device includes an optical fiber 10 having a certain length, which has a core 11 surrounded with a composite cladding including a low- refractive-index part 12 and a high-refractive-index part 13 and transmits light in waveguide mode. The two parts 12 and 13 of the cladding have lower refractive indexes than the core 11. In this case, a polymer upper coating 20 with selected optical characteristics surrounds the composite cladding. In a preferable practical style, the temperature reactivity of the long-cycle diffraction grating written to a conventional dispersion shift fiber is reduced to less than 0.40 nm/100 deg.C.
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公开(公告)号：JPH10221562A
公开(公告)日：1998-08-21
申请号：JP2450398
申请日：1998-02-05
Applicant: LUCENT TECHNOLOGIES INC
Inventor： REED WILLIAM ALFRED , VENGSARKAR ASHISH MADHUKAR
Abstract: PROBLEM TO BE SOLVED: To provide a WDM optical fiber communication system in which all channels have nominally zero color dispersion. SOLUTION: The transmission path includes (A) a first single mode optical fiber which has wavelengths λ1 ...λN and first code (+, -) non-zero color dispersion, (B) a second single mode optical fiber 13 which has wavelengths λ1 ...λN and is dispersion compensation type which has second code (-, +) non-zero color dispersion, and (C) a third single mode optical fiber 14 which has wavelengths λ1 ...λN and is called dispersion slope compensation type fiber (DSCF) which has dispersion slope.
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公开(公告)号：JPH10142412A
公开(公告)日：1998-05-29
申请号：JP28327597
申请日：1997-10-16
Applicant: LUCENT TECHNOLOGIES INC
Abstract: PROBLEM TO BE SOLVED: To manufacture the long-cycle optical fiber grating by a simple and inexpensive method by exposing an optical fiber to an electric arc at more than one positions along the length. SOLUTION: The optical fiber 20 is arranged across between a couple of electrodes 21A and 21B. The electrodes 21A and 21B are connected to a current source through a switch so as to generate an arc 22 between the electrodes. The optical fiber 20 is arranged at the center part between the two electrodes by an optical fiber holder which is controlled by a motor-driven stage. The optical fiber 20 is exposed repeatedly to the arc at successive positions along the length. This is carried out by turning off the current source, advancing the optical fiber in the holder, and igniting the arc again. When the optical fiber 20 is exposed to the electric arc, variation in refractive index is generated.
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10.发明专利
公开(公告)号：JPH1095628A
公开(公告)日：1998-04-14
申请号：JP13496297
申请日：1997-05-26
Applicant: LUCENT TECHNOLOGIES INC
Inventor： DIGIOVANNI DAVID JOHN , VENGSARKAR ASHISH MADHUKAR , WAGENER JEFFERSON LYNN , WINDELER ROBERT SCOTT
IPC: G02B6/00 , C03B37/012 , C03B37/027 , C03B37/028 , G02B6/02 , G02B6/036 , H01S3/067 , G02B6/10
Abstract: PROBLEM TO BE SOLVED: To obtain a new aperiodic optical fiber having microstructure. SOLUTION: When the difference Δ of effective refractive index between a core region and clad region is e.g. a high difference of >=5%, mode field diameter of a basic mode of
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