USA As Represented by Secretary of the Navy

Broadband Royalty Corporation

Arris Enterprises LLC

Arris Group, Inc.

Optinel Systems, Inc.

Sandeep T Vohra

Anthony Dandridge

Paul J Matthews

Alan B Tveten

Gregg A Johnson

Bruce A Danver

Bryan L Althouse

Irl N Duling

Alan D Kersey

Paul D Biernacki

Greg Nau

Evelyn Boettcher

Frank Bucholtz

Marc D Mermelstein

Chia Chen Chang

An arrangement is provided for transporting information from a central information distribution center (CIDC) to locations where such information is intended. Upon receiving a request for narrowcast information to be delivered to a node associated with a head end, the CIDC selects the requested information, generates an optical signal encoded with the requested information using information channels dedicated to narrowcast information transport for the node, and sends the optical signal to the head end via an optical fiber. When the head end receives the optical signal, the narrowcast information transport channels dedicated to the node are translated into subcarriers acceptable to the node before the requested narrowcast information is forwarded to the node.

Media stream distribution system

Agile block downconversion for the distribution of narrowcast services

Arrangements are provided for an amplitude balanced optical amplifier. A combination of an optical preamplifier and a gain/loss variation modification device (VMD) is employed. The gain/loss VMD compensates the gain variation across different wavelength channels introduced by the preamplifier. The gain/loss VMD operates based on a gain/loss profile that is complementary to that of the preamplifier. More than one amplifier may be deployed. In addition, feedback control may be applied to either the preamplifier or the gain/loss VMD to dynamically control the performance.

Amplitude balancing for multilevel signal transmission

A transmitter for optical communication systems includes a source of optical radiation, a source of complex non-information signals, and a modulator unit in communication with the source of optical radiation. The modulator unit is also in communication with the source of complex non-information signals. The modulator has an input adapted to receive information-bearing signals.

Efficient optical transmission system

An add-drop multiplexer is described, in one embodiment the add-drop multiplexer includes an optical transmission signal input port adapted to receive a wavelength division multiplexed optical transmission signal, an optical transmission signal output port adapted to output at least a portion of the wavelength division multiplexed optical transmission signal, an add-drop optical channel port adapted to receive an optical add channel and output an optical drop channel, and a wavelength selective optical filter arranged between the optical transmission signal input port, the optical transmission signal output port and the optical add-drop channel port. The wavelength selective optical filter reflects optical channels that will continue through the add-drop multiplexer along a transmission line to the optical transmission signal output port and permits an optical channel that is to be dropped to pass therethrough.

Dynamically reconfigurable add/drop multiplexer with low coherent cross-talk for optical communication networks

A tunable dispersion compensating device for optical communications systems has a compliant support block having a longitudinal axis and a load-receiving surface oriented substantially parallel to the longitudinal axis. The load receiving surface is suitable to receive an applied load in a direction substantially orthogonal to the longitudinal axis. A Bragg-grating fiber is disposed in the compliant support block and extends substantially along, and at an angle to, the longitudinal axis of the compliant support block.

Tunable dispersion compensating bandwidth device for fiber optics system

A passive, temperature compensated tunable filter calibration device in a Bragg-grating interrogation system. The invention comprises two systems: 1) a dual substrate Bragg grating calibration system, the temperature of an array of gratings is estimated using an array of gratings bonded to a common host substrate and a single grating bonded to a material with a different coefficient of thermal expansion; 2) a hydrogen cyanide wavelength reference absorption cell that absorbs light at discrete wavelengths corresponding to the molecular vibration mode frequencies of the gas. A first photodetector sees the transmission spectrum and a second sees the reflections from Bragg gratings in a sensing array. In this system there is no temperature compensation step as the absorption lines are not sensitive to temperature.

Passive, temperature compensated techniques for tunable filter calibration in bragg-grating interrogation systems

A tunable wavelength add/drop (t-WDM) device utilizes a multiwavelength input (which serves as a data input port), a low loss optical circulator or an optical coupler, a wavelength division de-multiplexer which splits the input multi-wavelength data stream into itsd individual components, a modified multi-channel DOS, a telecommunications grade optical fiber, and a wavelength multiplexer for adding optical data channels. The input multi-wavelength data stream from a network is sent to a wavelength de-multiplexer where it is demultiplexed into individual wavelengths which are applied to an array of Y-branch digital optical switching devices controlled by a computer. If a specific wavelength is to be dropped, it is diverted towards a branch of a given switch which has a fiber pig tail attached. If a specific wavelength is to be sent through (neither dropped or added) then the signal is diverted towards a mirrored end of the Y-branch, where it is reflected back towards the wavelength de-multiplexers to the circulator and goes out the output end of the t-WADM. If a wavelength 'slot' has ben vacated by a dropping channel then a new data stream may be added in that slot.

Tunable wavelength add/drop multiplexer based on integrated optic devices

A wavelength tunable filter for optical communication systems has an optical fiber containing a Bragg grating disposed within a compliant support block. A length of the fiber is wrapped in a spiral of fixed pitch around the longitudinal axis of a cylindrical polymer support block. The support block is placed within a support frame to which a micrometer screw assembly is attached and oriented to apply a variable mechanical load substantially parallel to the longitudinal axis of the cylindrical support block. Application of the load introduces a strain on the support block, changing the period of the refractive index in the fiber Bragg grating with a resulting shift in the Bragg reflection peak.

Wavelength tunable filter device for fiber optic systems

This invention pertains to a sensor comprising of glass optical fiber, a cellular pressure release material surrounding the fiber, and means for determining responsivity of the sensor, the sensor having responsivity of at least about &minus;160 dB re rad/m-&mgr;/Pa, which corresponds to sensitivity of about 50 times better than prior art. The sensor can be made part of an optical interferometer which is characterized by splitting of an entering light beam and measurement of an optical phase shift caused by light traversing different paths. The sensor can form a part of a fiber Bragg grating geometry characterized by a fiber Bragg grating in the glass fiber covered by the cellular pressure release material wherein shift of the Bragg wavelength induced by strain on to the cellular pressure release material is measured.

Coated fiber pressure sensors utilizing pressure release coating material

A bandwidth tunable fiber Bragg grating (FBG) device performs tuning in an optical transmission circuit by placing a grating in a compliant material, which is transversely loaded to create longitudinal strain through the Poisson effect of materials. Careful application of various load magnitudes along the length of the grating through the compliant material creates a strain gradient along the length of the grating, which chirps the grating thus resulting in altering the bandwidth of the grating. Tuning the grating bandwidth results, effectively, in tuning the dispersion of light being reflected off the grating. Insertion of such a device in the optical link allows for dynamic dispersion compensation in the link. The ability of the device to 'dial-in' a desired amount of dispersion is what makes it valuable.

Bandwidth tunable gratings for dynamic dispersion compensation in lightwave

A passive, temperature compensated tunable filter calibration device for a Bragg grating interrogation system. In a first system, a dual-substrate Bragg grating calibration system, the temperature of an array of gratings is estimated using an array of gratings bonded to a common host substrate and a single grating bonded to a material with a different coefficient of thermal expansion. Changes in a common temperature of the substrates is measured by monitoring the difference between shifts of grating wavelength. As a filter voltage is scanned from its lowest to its highest voltage, the voltages are recorded. The second lowest wavelength corresponds to the grating attached to the differing substrate. The voltages are used to calculate a voltage-to-wavelength function for the scanning range of the filter. To compensate for variations in a calibration curve and temperature variations of the calibration array, the temperature is estimated and function re-calculated at every pass of the scanning filter. In a second system, a hydrogen-cyanide wavelength reference absorption cell that absorbs light at discrete wavelengths corresponding to the molecular vibrational mode frequencies of the gas. With a broadband optical light input to the cell, the output displays the spectrum of the input with several narrow dips in the spectra corresponding to the absorption lines of the cell. A first photodetector sees the transmission spectrum and a second sees the reflections from Bragg gratings in a sensing array. The filter drive voltages that coincide with the dips of the transmission spectrum are used to calibrate the voltage-to-wavelength function of the scanning filter. In this system there is no temperature compensation step as the absorption lines are not sensitive to temperature.

The interferometric fiber optic accelerometer is viewed as a mass-spring transducer housed in a sensor case. The sensor case is attached to a moving part whose motion is inferred from the relative motion between the mass and the sensor case. A flexural disk is housed in a sensor case which is accelerated in a direction normal to the plate surface. The plate undergoes displacement resulting in strains on the plate surface. A coil of optical fiber, made to be part of an optical interferometer, is attached to the flexural disk, the strain from the disk is transferred to the fiber thus changing the path length of the fiber interferometer. The interferometer output in demodulated providing the acceleration response. The design of the accelerometer housing is such that it is highly immune to extraneous signals, i.e., dynamic and hydrostatic pressure. Fabrication of the optical fiber coils is accomplished by winding the optical fiber, with a specially designed chuck to form reference and sensing fiber coils which are then bonded to the flexural disk to form the accelerometer.

Fiber optic accelerometer sensor and a method of constructing same

A fiber optic sensor array has multiple segments, each capable of detecting a physical condition such as an acoustic wave. The segments are separated by weak reflectors such as fiber optic Bragg gratings. Light from a light source is input into the input end of the array. Light reflected by each of the reflectors has a phase shift representing the effects of the physical condition on all of the segments from the input end to that reflector. To address a specific reflector, the return light is demultiplexed. This demultiplexing is done by modulating the light input into the input end of the array with a pseudo-random bit sequence and correlating the output with a time-shifted version of the pseudo-random bit sequence to isolate the part of the output caused by that reflector. To address a specific segment, the phase shifts from two adjacent reflectors are determined. The return light can be strengthened by mixing it with a portion of the light picked off from the light source.

Coherent reflectometric fiber Bragg grating sensor array

The interferometric fiber optic accelerometer is viewed as a mass-spring nsducer housed in a sensor case. The sensor case is attached to a moving part whose motion is inferred from the relative motion between the mass and the sensor case. A flexural disk is housed in a sensor case which is accelerated in a direction normal to the plate surface. The plate undergoes displacement resulting in strains on the plate surface. A coil of optical fiber, made to be part of an optical interferometer, is attached to the flexural disk, the strain from the disk is transferred to the fiber thus changing the path length of the fiber interferometer. The interferometer output in demodulated providing the acceleration response. The design of the accelerometer housing is such that it is highly immune to extraneous signals, i.e., dynamic and hydrostatic pressure. Fabrication of the optical fiber coils is accomplished by winding the optical fiber, with a specially designed chuck to form reference and sensing fiber coils which are then bonded to the flexural disk to form the accelerometer.

Growing community of inventors

Ellicott City, MD, United States of America

Sandeep T Vohra