Ofs Fitel, LLC

Fitel USA Corporation

Bell Telephone Laboratories

Lucent Technologies Inc.

At&t Technologies, Inc.

American Telephone & Telegraph Co., At&t Bell Laboratories

At&t Bell Laboratories

Furukawa Electric North America, Inc.

Ofs Fitel Llc, a Delaware Limited Liability Company

Man Fei Yan

Benyuan Zhu

Patrick William Wisk

David John DiGiovanni

John Michael Fini

Thierry Franck Taunay

Jeffrey W Nicholson

David W Peckham

William Alfred Reed

Dennis J Trevor

Durgesh Vaidya

Peter Ingo Borel

Hung C Ling

Jorgen Ostgaard Olsen

Ole A Levring

James William Fleming

Jinkee Kim

Kazi S Abedin

Rasmus V S Jensen

John Burnette MacChesney

Andrew Douglas Yablon

Yaowen Li

George Edward Oulundsen, Iii

Thomas Edward Stockert

Tommy Geisler

Xinli Jiang

David J Kudelko

Paul Francis Glodis

Matthew Julius Andrejco

Katherine Theresa Nelson

Warren W Rhodes

Roman Shubochkin

Raja A Ahmad

Kasyapa Balemarthy

Kim Willard Womack

Paul S Westbrook

Kenneth L Walker

David W Johnson, Jr

Lars Gruner-Nielsen

Robert M Atkins

Clifford E Headley

Yi Sun

Robert L Lingle

Xiaoguang Sun

Jie Li

Bera Palsdottir

Pang-Dow Foo

James Dennis Wynn

Tai-Chan D Huo

Gregory M Bubel

Ryan Tyler Bise

Kyle R Bedard

Susanne Dyrbol

Lucas Hsu

Rasmus V Jensen

Stanley F Marszalek

Steven Alan Jacobs

David J Digiovanni

Thierry F Taunay

George E Oulundsen

Durgesh Shivram Vaidya

Disclosed herein is a method comprising injecting light of a first wavelength &#x3bb;into a wavelength division multiplexer; injecting light of a second wavelength &#x3bb;into the wavelength division multiplexer; combining the light of the first wavelength &#x3bb;and the light of the second wavelength &#x3bb;in the wavelength division multiplexer to produce light of a third wavelength &#x3bb;; and reflecting the light of the third wavelength &#x3bb;in a dual-Brillouin peak optical fiber that is in communication with the wavelength divisional multiplexer; wherein the dual-Brillouin peak optical fiber has at least two Brillouin peaks, such that an amplitude Aof at least one of said Brillouin peaks is within 50% to 150% of an amplitude Aof another Brillouin peak 0.5A2&#x2264;A&#x2264;1.5A; wherein the dual-Brillouin peak optical fiber generates a Brillouin dynamic grating that reflects an improved back-reflected Brillouin signal of the combined light.

Brillouin dynamic grating generation using dual-Brillouin-peak optical fiber

An optical preform manufacturing process is disclosed in which an alkali dopant is deposited between an optical fiber core rod and an optical fiber cladding jacket. Depositing the alkali dopant between the core rod and the cladding jacket permits diffusion of the alkali dopants into the core during fiber draw when the core and the cladding are at their respective transition (or vitrification) temperatures. Introduction of the alkali dopants between the core rod and the cladding jacket also permits decoupling of the alkali doping process from one or more of other optical preform manufacturing processes. The optical preform manufacturing process can also include placing alkali dopants between an optical fiber inner cladding jacket and an optical fiber outer cladding jacket to reduce the glass viscosity during fiber draw.

Viscocity-reducing dopants in optical fibers

A higher-order mode (HOM) fiber is configured as a polarization-maintaining fiber by including a pair of stress rods at a location within the cladding layer that provides for a sufficient degree of birefringence without unduly comprising the spatial mode profile of the propagating higher-order modes. An optical imaging system utilizing polarization-maintaining HOM fiber allows for different wavelength probe signals to be directed into different modes, useful in applications such as STED microscopy, 2D sensing, and the like.

Polarization-maintaining fiber device supporting propagation in large mode field diameters

An optical fiber has a core region that is doped with one or more viscosity-reducing dopants in respective amounts that are configured, such that, in a Raman spectrum with a frequency shift of approximately 600 cm, the fiber has a nanoscale structure having an integrated D2 line defect intensity of less than 0.025. Alternatively, the core region is doped with one or more viscosity-reducing dopants in respective amounts that are configured such that the fiber has a residual axial compressive stress with a stress magnitude of more than 20 MPa and a stress radial extent between 2 and 7 times the core radius. According to another aspect of the invention a majority of the optical propagation through the fiber is supported by an identified group of fiber regions comprising the core region and one or more adjacent cladding regions. The fiber regions are doped with one or more viscosity-reducing dopants in respective amounts and radial positions that are configured to achieve viscosity matching among the fiber regions in the identified group.

Optical fiber with low loss and nanoscale structurally homogeneous core

A higher-order mode (HOM) fiber is configured as a polarization-maintaining fiber by including a pair of stress rods at a location within the cladding layer that provides for a sufficient degree of birefringence without unduly comprising the spatial mode profile of the propagating higher-order modes. Long-period gratings are used as mode couplers at the input and output of the PM-HOM fiber, where the gratings are formed by exposing areas of the core region orthogonal to the position of the stress rods. The diameter of the stress rods (D) and displacement of the rods from the center of the core region (R) are controlled to yield a configuration with an acceptable birefringence and polarization extinction ratio (PER) within the HOM fiber, even in situations where the fiber is bent (a bend radius less than 50 cm).

The core region of an optical fiber is doped with chlorine in a concentration that allows for the viscosity of the core region to be lowered, approaching the viscosity of the surrounding cladding. An annular interface region is disposed between the core and cladding and contains a concentration of fluorine dopant sufficient to match the viscosity of the core. By including this annular stress accommodation region, the cladding layer can be formed to include the relatively high concentration of fluorine required to provide the desired degree of optical signal confinement (i.e., forming a 'low loss' optical fiber). The inclusion of the annular stress accommodation region allows for the formation of a large effective area optical fiber that exhibits low loss (i.e., &#x3c;0.19 dB/km) in both the C-band and L-band transmission ranges.

Low loss optical fiber and method of making the same

An optical pedestal fiber is configured to be taperable to form a tapered fiber having a mode field diameter at the tapered end that differs from the mode field diameter at the untapered end in correspondence with the difference between the cladding diameter at the tapered end and the cladding diameter at the untapered end. A plurality of such pedestal fibers can be used to construct a tapered fiber bundle coupler that provides matching of both core pitch and mode field diameter between a plurality of input fibers and individual cores of a multicore fiber. Further, the tapered fiber bundle coupler can be constructed using a plurality of fibers, in which individual fibers are configured to have different effective refractive indices, thereby suppressing crosstalk therebetween.

Techniques and devices for low-loss coupling to a multicore fiber

Described is a technique for the design and manufacture of MMFs. Designs are implemented so as to limit the maximum variation in z(r, &#x3bb;) with respect to wavelength, where z(r, &#x3bb;) is the dielectric constant weighted by the square of the wavelength. MMFs for use in CWDM applications are specifically described.

Manufacture of multi-mode optical fibers

The core region of an optical fiber is doped with chlorine in a concentration that allows for the viscosity of the core region to be lowered, approaching the viscosity of the surrounding cladding. An annular interface region is disposed between the core and cladding and contains a concentration of fluorine dopant sufficient to match the viscosity of the core. By including this annular stress accommodation region, the cladding layer can be formed to include the relatively high concentration of fluorine required to provide the desired degree of optical signal confinement (i.e., forming a 'low loss' optical fiber).

An optical fiber-based sensor is described that is suitable for operation in a gas-rich environment. The sensor comprises a chamber into which are mounted one or more segments of optical fiber, into which are inscribed a plurality of sensor gratings. Each of the plurality of sensor gratings is configured to have the same wavelength shift over time in response to a change in gas diffusion, such that gas diffusion parameters are excluded in the determination of the respective amount of change in temperature, applied strain, and gas diffusion. Also described is a fiber, and techniques for making same, comprising of cores extend through a common cladding. The cores are doped so as to create, in conjunction with the cladding, a plurality of waveguides having the same wavelength shift over time is response to a change in gas diffusion, but different wavelength shifts in response to changes in other parameters.

Grating-based sensor

Described is a design approach to fabricating broadband graded-index multimode fibers where the concentration profile of at least one dopant in the core region includes at least one flat-zone. Designs for use in CWDM applications are also disclosed.

Broadband multi-mode optical fibers with flat-zone in dopant concentration profile

A few-moded fiber device has several discrete sections of few-moded fibers that are separated by mode converters, with each mode converter accomplishing mode conversion between one or more pairs of modes. The mode conversions can be accomplished using a sequence, such as a periodic or cyclic sequence that would cause (1) a signal wave launched with any mode to assume every other mode for one or more times; (2) the number of times the signal remains in any modal state is substantially the same; and (3) the net signal gain or loss or group delay of the input signal is substantially the same regardless of the state of input mode. A laser few-mode amplifier is provided. An optical transmission system is also provided.

Few moded fiber device employing mode conversion

A discrete Raman amplifier comprises a Raman gain fiber, an input port into the Raman gain fiber for receiving optical signals to be Raman amplified, and an output port out of the Raman gain fiber for emitting Raman-amplified optical signals. A pump light input provides pump light to the Raman gain fiber at a plurality of wavelengths so as to provide Raman amplification over the selected signal wavelength range. Within both the pump light wavelength range and the selected signal wavelength range, the Raman gain fiber has only positive chromatic dispersion, and the Raman gain fiber has a moderate effective area.

Discrete raman amplifier

An optical fiber has two or more core regions disposed within a common cladding region. Each of the core regions is configured to guide a respective light transmission comprising at least one optical mode along the length of the fiber. The cores are arranged within the common cladding region according to a core configuration that substantially prevents crosstalk between modes of neighboring cores in the fiber, in a deployment of the fiber in which cross-coupling between neighboring cores is affected by perturbations arising in the deployed fiber.

Techniques for reducing crosstalk in multicore fibers

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Berkeley Heights, NJ, United States of America

Man Fei Yan