Abstract: A device for measuring movement of an object (15) and the device relative to each other. The device comprises a laser (3) for generating a measuring beam (13), which is converged by a lens (10) in an action plane. Radiation reflected by the object (15) is converged to re-enter the laser cavity to generate a self-mixing effect in the laser (3). Measuring means (4) are provided to receive the reflected measuring beam radiation and enable the frequency difference between the measuring beam (13) and the reflected measuring beam radiation to be determined, which is representative of the relative movement.

Abstract: An optical input device for measuring relative movement between an object (15) and a sensor unit comprising a laser device (3, 5) having a laser cavity for emitting a measuring beam (13, 17) and a respective radiation-sensitive detector (4, 6) for generating a measurement signal representative of changes in the operation of the laser device (3, 5) as a result of measuring beam radiation re-entering the laser cavity. A sensor unit is provided for measuring relative movement along each measuring axis in an action plane, and the resultant measurement signal from one or each of the sensor units is used to determine distance and/or movement of the input device and the object (15) relative to each other along a measuring axis transverse to the action plane by summing the offset frequency of a rising and falling slope of the measurement signal.

Abstract: A method and optical module for measuring relative movement of an input device and object (15) along at least one measuring axis. A laser device (3) having a laser cavity is provided for generating a measuring beam (13) in respect of each measuring axis. The measuring beam (13) is used to illuminate the object (15) and measuring beam radiation reflected from the object (15) and re-entering the laser cavity generates a self-mixing effect in the laser and causes changes in operation of the laser cavity. A detector (4) is used to generate a measurement signal representative of these changes and an electronic processing circuit (18) selects, in dependence on the speed of relative movement, one of at least two parameters of the measurement signal for use in determining the speed and direction of relative a movement.

Abstract: One or more of a topology location test and a distance test are applied to determine if a CPE device has moved in a cable plant. An indication of service fraud is provided if the CPE topology location or distance test indicate an unauthorized CPE device move.

Abstract: Optical transmitter/receivers for use in a DWDM systems are provided. Transmission of data signals in a quadrature-return-to-zero (QRZ) format achieves a data transmission rate equal to eight times a base data rate, i.e., 80 Gbps over a 100 GHz channel if the base data rate is 10 Gbps, with high non-linear performance by setting the polarization state of the data bands such that non-linear effects induced by PMD are reduced. Additionally, a transmitter achieves a transmission data rate equal to 16 times the base data rate by sharpening the QRZ pulses and interleaving pulse-sharpened QRZ data signals in the time domain, further doubling the data rate. Using counterpropagation in the transmitter, carrier signals and data signals traverse the same length of fiber, reducing fringing effects in the transmitter. Related techniques enhance reception and detection of data at high data rates. A local pulse-sharpened carrier is mixed with a QRZ data signal at a detector reducing amplification noise by a factor of two.

Abstract: A diagnostic and prescriptive system and method for management of a combined optical and RF cable plant system. In an exemplary embodiment the method and system uses optical receivers in a hub or headend to determine a variety of cable plant parameters such as the OMI of the received signal and automatically facilitated prescriptive service through prioritization and automatic recalibration. In another exemplary embodiment the method allows doing such signal OMI measurements in a closed loop system (that is a fully operational system). In addition, a further exemplary method and system allows storing of standard receiver calibration information such that from thereon signal OMI measurements that can be performed without signal interruption.

Abstract: A hybrid fiber cable network includes multiple nodes, each of which receives a first multi-carrier return signal from multiple customers with carrier signals in a first frequency band. In a fiber-hub, one or more first multi-carrier signals are converted into a second multi-carrier signal with carrier signals in a second band. Each information signal modulates a different higher frequency carrier signal in the second signal. A multitude of second multi-carrier signals are converted into optical signals with different optical wavelengths, multiplexed onto an optical fiber, and transmitted to the head-end. The first frequency band is below 200 MHz, preferably from 5 to 50 MHz. The second frequency band is above 200 MHz, preferably between 300 and 1200 MHz to reduce crosstalk due to stimulated Raman scattering (SRS). Preferably, each second frequency band is no more than one octave wide, and more preferably, no more than one half an octave wide.

Abstract: The present invention relates generally to an amplifier such as that with the radio frequency (RF) spectrum having a nonlinear feedback loop to cancel out distortions in the input signal, and method therefor.