Fitel USA Corporation

Ofs Fitel, LLC

Ii-vi Incorporated

Furukawa Electric North America, Inc.

Interfiber Analysis, LLC

Jayesh C Jasapara

Andrew Douglas Yablon

David John DiGiovanni

Christopher Stephen Koeppen

Michael Cahill

Glenn Bartolini

Ryan Tyler Bise

David J Digiovanni

A multiport optical switch (such as an N&#xd7;1 switch) is used to controllably select a specific incoming optical signal that is to be processed by an associated optical channel monitor (OCM). The OCM includes a tunable optical filter and photodetector arrangement, and is configured to measure the optical spectrum of the incoming optical signal and extract information associated with the various optical channels (wavelengths) forming the incoming optical signal (i.e., power, wavelength, OSNR and the like for each channel). The OCM also includes a signal processing component that generates a pair of output control signals, a first signal to control the wavelength scanning process of the tunable optical filter and a second signal to control the setting of the multiport optical switch.

Optical channel monitor with integral optical switch

A mode filter for eliminating the propagation of higher-order modes along a section of optical multimode fiber comprises a graded index (GRIN) lens, preferably of a quarter-pitch length, and a pinhole element in the form of a small core fiber. This configuration creates a Fourier spatial filter assembly that removes higher order modes propagating along an optical fiber while capturing the fundamental mode of the optical signal. A section of GRIN fiber is preferably used as the lens, with the small core fiber disposed at the output of the GRIN fiber lens to collect substantially only the on-axis fundamental mode of the optical signal. Since the higher order modes are shifted away from the origin by the GRIN fiber lens, only the fundamental mode signal is captured by the small core fiber.

Spatial filtering of higher order modes in multimode fibers

Subject matter disclosed herein relates to measuring modes of a waveguide.

System and/or method for measuring waveguide modes

The specification describes optical fiber designs that overcome the problem of self-induced damage to optical fibers due to excessive self-focusing. The refractive index of these fiber designs is grossly non-uniform in the center core of the optical fiber. In one embodiment, the optical fiber is designed with a deliberate and steep core trench. In addition, the nominal core region of these optical fibers has a very large area. The combination of these two properties restricts a large portion of the optical power envelope to a core ring, with reduced optical power inside the core ring. These designs substantially reduce self-focusing in the optical fiber. Photonic systems employing optical fibers having these modified core designs are expected to be especially effective for transmitting high power, e.g., greater than 1 MW, with short pulse duration.

Optical fibers for high power applications

A fiber characterization arrangement utilizes Fourier domain optical coherence tomography (FDOCT) to measure the cross-section of optical fibers, thus providing information sub-surface features, coating thickness/concentricity and stress-induced birefringence under tension. The FDOCT technique can also be used to study microstructured fibers. By making FDOCT measurements on a fiber placed in a cavity, the geometric and optical thickness of the fiber can be simultaneously measured, allowing for the determination of the refractive index of the fiber.

Characterization of optical fiber using Fourier domain optical coherence tomography

A method and apparatus for measuring the optical thickness and absolute physical thickness of an optically transparent object utilizes a reflective interferometric process. A broadband optical signal is directed toward the object to be measured, and a pair of signals reflected off of the object are processed to determine the optical thickness of the object. When used with an optical fiber preform, the technique can be used to measure the outer diameter of the preform and control the drawing process. If the index of refraction of optically transparent object is known, the absolute physical thickness can also be determined.

Method for measuring the optical and physical thickness of optically transparent objects

A photonic band gap fiber structure is formed to include a plurality of filled air holes surrounding a solid silica core region. The material used to fill the air holes is chosen to exhibit an index of refraction that is greater than the index of the core, where the fill material refractive index is also adjustable as a function of temperature. Therefore, by adjusting the temperature of the PBG fiber, the dispersion characteristic of the propagating signal can be modified.

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North Plainfield, NJ, United States of America

Jayesh C Jasapara