Laser diode light source
Granted: February 3, 2015
Patent Number:
8948222
A light source including a laser diode, and a method of operating a light source including a laser diode are disclosed. A driving current of the laser diode is dithered to cause a near-field light intensity distribution at an end facet to be perturbed, thereby reducing a time-averaged local intensity of the laser light at the end facet of the laser diode. The reduced time-averaged intensity reduces a possibility of a damage of the end facet.
Method and system for determining a number of load coils in a transmission line
Granted: December 23, 2014
Patent Number:
8917818
A method and system for determining a number of load coils in a transmission line are provided. An impulse response of the transmission line is calculated from a characteristic impedance of the transmission line. A number of complex conjugate pole pairs of a transfer function of the impulse response is then determined. Thereby, the number of load coils in the transmission line, which is equal to the number of complex conjugate pole pairs, is determined.
Apparatus and method for enriching data records in a telecommunications network
Granted: December 16, 2014
Patent Number:
8913595
An apparatus for enriching data records based on messages monitored on a telecommunications network having an Internet Protocol (IP) portion includes a data record enrichment module for receiving data records from a data record builder. The data records include at least a subscriber identifier field and a handset type identifier field and the data enrichment module stores a table mapping subscriber identifiers with the handset type identifiers. When a received data record includes a…
Reducing transients in an optical amplifier
Granted: December 9, 2014
Patent Number:
8908264
A controller for reducing a transient variation of gain of an optical amplifier is disclosed. The controller includes a control circuit adapted to generate an electrical signal mimicking optical gain transient variation upon an abrupt change in input loading conditions. The electrical signal is applied to a variable optical attenuator disposed downstream of the active optical fiber of the optical amplifier. The control circuit can be realized in a variety of ways, but preferably it…
Large mode area optical waveguide devices
Granted: December 9, 2014
Patent Number:
8908263
A very large more area active double clad optical waveguide doped with Nd3+ at a concentration of at least 0.1% by weight can be used to effectively amplify light at a wavelength of between 1050 nm and 1120 nm. At a doping concentration sufficient to provide a net optical absorption of at least 3 dB/m for the pump light at the wavelength of 795 to 815 nm or 883 to 887 nm, Nd3+ operates under much lower inversion levels than Yb3+. Due to the lower inversion levels, the Nd3+ doped…
Photovoltaic cell
Granted: December 2, 2014
Patent Number:
8901412
The disclosure relates to multiple quantum well (MQW) structures for intrinsic regions of monolithic photovoltaic junctions within solar cells which are substantially lattice matched to GaAs or Ge. The disclosed MQW structures incorporate quantum wells formed of quaternary InGaAsP, between barriers of InGaP.
Graphical user interface adjusting to a change of user's disposition
Granted: November 18, 2014
Patent Number:
8890812
A user interface apparatus and a method for adjusting the apparatus are disclosed. A position and/or a viewing angle of the user is tracked, and graphical interface objects are adjusted to keep them visible at different user's distances and viewing angles. For example, as the user steps away from the display, the objects on the display can be proportionally enlarged to make them appear of the same size to the user. The sensitivity of a gesture recognition system to the user's movements…
Broadband dielectric reflectors for LED with varying thickness
Granted: November 18, 2014
Patent Number:
8889517
A broadband, omnidirectional, multi-layer, dielectric reflector for an LED in a white light emitting device provides both near 100% reflectivity across the visible spectrum of light, and electrical insulation between the substrate and the electrical circuitry used to power and control the LED. When a sealant material, having a higher index of refraction than air, is used to protect the LED and the accompanying electrical circuitry, an aluminum reflector layer or substrate is provided to…
Biaxial MEMS mirror with hidden hinge and staggered electrodes
Granted: November 11, 2014
Patent Number:
8885245
A multi-layer hidden hinge and actuator design for high fill factor biaxial MEMS mirror array for wavelength selective switches (WSS) including a coarsely aligned orthogonal vertical comb drive and/or parallel plate actuator. Each micro-mirror in the MEMS linear piano micro-mirror array comprises a reflective body/mirror layer, a ground/hinge layer and a hot electrode/substrate layer. To increase the amount of surface area available for the hot and ground electrodes, the dimensions of…
Monitoring QAM impairments in digital communications
Granted: November 4, 2014
Patent Number:
8879669
A diagnostic data acquisition system for analyzing impairments in a QAM digital communication system is triggered by diagnostic data generated by a QAM demodulator when demodulating a QAM signal. Upon triggering, the data acquisition system can capture the diagnostic data used for triggering, and/or some other diagnostic data. The captured data may be stored for subsequent analysis to determine a probable cause of the impairment.
Stabilizing beam pointing of a frequency-converted laser system
Granted: November 4, 2014
Patent Number:
8879589
A beam-stabilized laser system using optical frequency conversion in a nonlinear optical crystal is disclosed. An optimal phase-matching angle in the crystal depends on both wavelength and temperature. If the crystal temperature changes, the optimal phase-matching direction will change as well. A different wavelength can be selected so that the optimal phase-matching occurs along the original beam path and returns the output beam to the original direction. Thus, a central wavelength of…
High resolution wavelength measurement system using a coarse, stable timing signal
Granted: November 4, 2014
Patent Number:
8879054
A source generates an optical test signal sweeping a bandwidth of wavelengths over time. The test signal is applied to a device under test (DUT) to generate a response signal. A timing signal generator connected to the source generates a timing signal having triggers at time instances corresponding to known wavelengths of the test signal. A DUT detector samples the DUT response signal generating sampled DUT data using a sampling period that is shorter than a shortest time between timing…
Apparatus and method for monitoring a telecommunications network
Granted: October 28, 2014
Patent Number:
8874720
A method and apparatus for monitoring telecommunications network elements, especially where direct access to those network elements is not available. The invention allows a network manager to build and maintain significant relationship information, as well as model the state of network elements with a high degree of accuracy, but based only on the information contained within the transactions built from the network traffic which is being monitored. In particular, it allows the network…
Wavelength selective switch
Granted: October 28, 2014
Patent Number:
8873904
A wavelength selective switch according to the present invention includes at least one input port for inputting wavelength-multiplexed light, a dispersive element which receives the light from the input port, and disperses the received light, a light converging element which converges dispersed light which has been dispersed for each wavelength, a light deflecting member having a plurality of reflecting optical elements which are capable of independently deflecting each dispersed light…
Dual polarization optical modulator using dual broadband multi-electrode weighted direct analog phase modulators
Granted: October 28, 2014
Patent Number:
8873896
An electro-optical phase modulator, dual polarization modulator applying that modulator and a phase modulation method are disclosed. A waveguide in an electro-optical substrate has at least two electrodes for modulating the waveguide. Each electrode receives a sequential bit of a precoded digital input and forms a shifting line from a first input end through interaction lengths near the waveguide causing modulation, shifted lengths distal from the waveguide for avoiding modulating the…
Method and sputter-deposition system for depositing a layer composed of a mixture of materials and having a predetermined refractive index
Granted: October 21, 2014
Patent Number:
8864958
A method and sputter-deposition system for depositing a layer composed of a mixture of materials and having a predetermined refractive index are provided. The sputter-deposition system includes a plurality of target cathodes, each of which comprises a target material having a different composition, that are powered by a single DC power supply. The plurality of target cathodes are cosputtered to deposit a layer composed of a mixture of materials on a substrate. The composite refractive…
Tunable Bragg grating and a tunable laser diode using same
Granted: October 14, 2014
Patent Number:
8861556
A spatially modulated waveguide Bragg grating mirror is suspended over a substrate by plurality of fingers extending laterally away from the waveguide centerline. The positions of the fingers are coordinated with the positions of crests and valleys of amplitude or phase modulation of the Bragg grating, to avoid disturbing the Bragg grating when it is tuned by heating. When the Bragg grating is heated, the heat flows through the fingers creating a quasi-periodic refractive index variation…
High-speed feedthrough having a stair-like shape transmission line formed through a multi-layer substrate
Granted: September 30, 2014
Patent Number:
8847698
A high-speed feedthrough (HSFT) is disclosed for transmitting a signal having a highest frequency of at least 10 GHz between first and second locations separated by a vertical distance of at least approximately half of the shortest transmitted wavelength, and separated by a horizontal distance. A substrate structure includes multiple stacked layers. An RF transmission line is connected through the structure between the first and second locations for transmitting the signal. The RF…
Wavelength selective switch
Granted: September 30, 2014
Patent Number:
8849077
A wavelength selective switch includes a light input output portion having an input port and an output port for wavelength-multiplexed light, which are arranged in an array form in a first direction, a light dispersive unit which separates the wavelength-multiplexed light input from the input port, into signal wavelengths, a condenser element which condenses light separated into the signal wavelengths, and a light deflective element array which deflects the signal light in the first…
Optical waveguide modulator
Granted: September 30, 2014
Patent Number:
8849071
The invention relates to waveguide optical modulators wherein two or more waveguides are modulated with specific modulation strengths using a single straight signal electrode or a single multi-segment signal electrode. Modulation strengths for each of a plurality of waveguides modulated by a single multi-segment electrode are matched over a wide modulation frequency range. Linearized output characteristics with respect to second and third order distortions arc achieved in one aspect of…
