Lucent Technologies Inc.

Other

Fitel USA Corporation

William Robert Holland

Stanley K Pau

Jungsang Kim

Jane Deborah LeGrange

Ranjan Dutta

Ruben Travieso

George F Deveau

Gary E Carver

John V Gates, Ii

Linda M Braun

Mario Eugene DeAngelis

In accordance with the invention, a high-resolution variable optical delay line comprises an optical switch, such as an optical micromechanical mirror switch, and an array of delay fiber paths. Each delay fiber path in the array comprises a region where the fiber is curved differently from the other fibers in the region and a reflector. Each fiber path advantageously comprises other regions where the fiber is essentially parallel to the other fibers in the region. Each fiber is curved differently from the others in order that the fiber paths each provide a different delay.

Variable optical delay lines and methods for making same

A method of calibrating a crossconnect including a MEMS device and another optical device, each of which further include a plurality of elements, the method including determining a relationship between an applied voltage and an angle response for a number of the elements of the MEMS device, determining a function of beam position and element position for the number of the elements of the MEMS device, assembling the MEMS device and the another optical device to produce the crossconnect, applying voltages to make sample connections between the MEMS device and the another optical device based on the relationship and the function, determining a transformation for the sample connections caused by packaging the crossconnect, and redetermining the relationship and the function based on the transformation. The method may be iterated more than once to achieve a more accurate determination.

Method for calibrating a MEMS device

A time-division multiplexed optical signal is routed to several input ports of a MEMS-mirror Optical Cross connect (OXC). Advantageously, a single optical signal can be routed through fiber delay coils of varying lengths to introduce precise delay to an optical pulse such that the optical pulse is fed to the input ports of the OXC at various timeslots. After switching the optical pulses through the OXC, the switched optical pulse at different timeslots is combined (multiplexed) and thereafter detected. The amount of optical energy in the (combined) received (output) enables the calibration or training of the OXC. The circuit may be reconfigured to measure the amount of cross talk (signal leakage), insertion loss, and time delay that the OXC introduces in the system.

System and method to calibrate an optical cross-connect

The present invention is directed to an optical time-domain reflectometer which employs a so-called &ldquo;out-of-band&rdquo; offsetting to cancel the effects of Raman non-linearities which extract energy from the traffic signal wavelengths and amplify the test signal back-scattering. Losses and faults in the optical fibers are monitored by measuring the back-scattered portion of the light launched into the fiber, with the test signal back-scattering judiciously offset to account for the Raman non-linearities. That is, the effects of the Raman non-linearities are taken as a baseline measurement and, then accordingly used as a basis to offset the test signal back-scattering.

Optical time-domain reflectometer (OTDR)

The present invention employs polarizers and delay elements to effect the real-time measurement of optical parameters required to compute the polarization mode dispersion (PMD) in an optical fiber. The measurement is performed in situ and based on the remote sensing of the intensity levels of optical pulses transmitted through two polarizers deployed along the fiber for different known states of polarization at each of two wavelengths. In as much as information about the output states of polarization of the optical pulses contained in these latter intensity transmission measurements are made substantially coincident with the location of the polarizers, the return propagation of the optical pulses does not affect the measured polarization characteristics of the fiber.

In situ polarization mode dispersion measurement

The present invention is an optical spectrum analyzer (OSA) comprising a tree-structure of N-stage wavelength filters or &ldquo;wavelength slicer&rdquo; which &ldquo;slice&rdquo; the incident optical signal into desired groupings of individual sliced spectral components, each along a different output optical fiber. Cascaded fiber Bragg gratings and delay lines coupled to each output optical fiber then uniquely map the &ldquo;sliced&rdquo; spectral components into the time domain such that each spectral component is allocated a unique time slot.

Optical spectrum analyzer

The present invention employs &ldquo;polarization markers&rdquo; deployed immediately after the branching portion of a passive optical network (PON) for measuring and monitoring transmission losses and faults. Each polarization marker is configured to produce a unique polarization dependent loss (PDL) within the corresponding branch of the PON. Since each polarization marker uniquely attenuates optical test pulse(s) launched into the PON, the back-scattering uniquely varies with the launched state of polarization. Losses within each branch of the PON are then monitored by measuring the back-scattered portion of the launched optical pulse(s) as a function of time for different known states of polarization, wherein the unique PDL associated with each polarization marker is used as the basis for distinguishing the branches from one another.

Test and measurement system for detecting and monitoring faults and losses in passive optical networks (PONs)

A multi-fiber optical delay line incorporates a plurality of optical fibers nestedly positioned and affixed to a planar substrate. The fibers include input portions that are linearly and proximately positioned on the substrate, and of equivalent length. The fibers also include output portions that are linearly and proximately positioned on the substrate, and of equivalent length. The input and output portions of each fiber are interconnected by a u-shaped connecting portion, and each connecting portion is positioned to have a unique and predetermined length. The predetermined lengths are selected such that differences in length between a shortest fiber and another fiber in the plurality of fibers are equivalent to a fiber length that would be traversed by the input signal during a time period required for the transmission of a predetermined number of bits in the digital signal. The input portions of the fibers are coupled to an optical splitter which provides one copy of an input signal substantially simultaneously to each of the input portions. In a preferred embodiment of the invention, a planar heater and overcoating are used to control the thermal profile across the plurality of fibers.

Multi-fiber digital delay line

Methods and devices are provided for quickly producing all possible linear polarization states of light at the output of a length of optical fiber. Linearly polarized light is input and is transmitted through a fiber. Due to the birefringence of the fiber, light at the output of the fiber is elliptically polarized irrespective of the input polarization. The elliptically polarized states of light at the output are generated as an arbitrary circle on an output Poincare sphere. This arbitrary circle is then manipulated to produce a final circle substantially coinciding with the equator of the Poincare sphere. This final circle represents all possible linear polarization states at the output of the fiber. The invention eliminates the need for determining transformation matrices and performing point-by-point calculations in order to obtain input polarization settings for polarization-based, passive optical network (&ldquo;PON&rdquo;) testing.

Methods and systems for producing linear polarization states of light at the end of a length of optical fiber

The present invention provides a method and apparatus for interfacing optical fiber cables with an optical integrated circuit. The apparatus comprises a flexible substrate having optical fibers fixedly arranged therein in a predetermined manner such that the distal ends of the optical fibers are disposed in groups on the outer periphery of the substrate to facilitate joining of the fibers with optical fibers of the optical fiber cables or ribbons using mass joining techniques. Once the optical fibers have been arranged in the substrate, the optical integrated circuit is mounted in the substrate. The substrate has an opening formed therein for receiving the optical integrated circuit. Once the optical integrated circuit has been mounted in the substrate, the proximal ends of the fibers fixed in the substrate are optically coupled to the ports of the optical integrated circuit.

Method and apparatus for interfacing optical fibers from optical fiber

An electronic article surveillance and identification system employing a transceiver (10,11) for broadcasting an interrogation signal into a zone to track the location and movement therein of inventory, merchandise, vehicles, animals, people and objects carrying passive (unpowered) transponder tags (12) adapted to receive the interrogation signal, process the signal in an encoded surface acoustic wave device (15) having a predetermined pattern of reflection groove or grating transducers (30-39, 40-72) and echo an encoded response signal to the transceiver.

Growing community of inventors

Warrington, PA, United States of America

William Robert Holland