Method of determining an optical distance for chromatic dispersion compensation
Granted: December 20, 2011
Patent Number:
8081877
A method of determining an optical distance between two nodes of an optical network for chromatic dispersion compensation includes using existing optical supervisory channel components in each node to measure the “time-of-flight” of an optical signal having a known wavelength. The effective optical distance is determined based on the time-of-flight and known wavelength of the optical signal. The computed optical distance may then be used to compensate for the dispersion experienced…
Optical wavelength selective router
Granted: December 13, 2011
Patent Number:
8078019
A fiber-optical, wavelength selective switch, especially for channel routing with equalization and blocking applications. The input signals are converted to light beams having predefined polarizations (41). The beams are then laterally expanded (43), and then undergo spatial dispersion in the beam expansion plane. The different wavelength components are directed through a polarization rotation device, pixilated along the wavelength dispersion direction such that each pixel operates on a…
Liquid crystal optical switch configured to reduce polarization dependent loss
Granted: November 22, 2011
Patent Number:
8064036
An optical device has the structure to perform switching and attenuation of an optical beam with reduced polarization dependent loss (PDL). The optical device includes a birefringent displacer and two liquid crystal (LC) structures. The first LC structure is used to condition s-polarized components of the optical beam and the second LC structure is used to condition p-polarized components of the optical beam. Each LC structure has a separate control electrode so that the s-polarized…
Wavelength division multiplexed systems with optical performance monitors
Granted: September 27, 2011
Patent Number:
8027583
The specification describes optical performance monitors which are simplified by coupling single tunable optical filters to multiple channels being monitored. Optical measurements for more than one channel may be made simultaneously. The optical system architecture is preferably an optical performance monitor for a WDM system. In a system designed according to the invention n channels may be monitored using n photodetectors, n optical splitters, but only n/2 tunable optical filters.…
High extinction ratio and low crosstalk compact optical switches
Granted: September 6, 2011
Patent Number:
8014067
An improved optical switch utilizes one polarization modulator, with the beam components traversing it twice. Because of the twice traverse, the extinction ratio of the switch is doubled without the addition of another polarization modulator, thus avoiding the costs of additional optical components. With no additional components, the switch is more compact than conventional switches with the same extinction ratio. Fewer components also result in more thermal and long-term stability and…
Fast power transient supression in constant power-mode controlled optical amplifiers
Granted: June 14, 2011
Patent Number:
7961380
The specification describes an improved approach to suppressing fast transients in optical amplifier systems. The approach relies on operating the amplifier in an automatic power-mode control with an extra loss component. It is applicable to optical amplifiers based on rare earth amplifier media, such as erbium doped fiber amplifiers (EDFAs).
System and method for tunable chromatic dispersion compensation
Granted: May 24, 2011
Patent Number:
7949257
One embodiment sets forth a technique for measuring chromatic dispersion using reference signals within the operational range of amplifiers used to refresh data signals. One red/blue laser pair in the transmission node is used for measuring dispersion and chromatic dispersion compensation is added at each line node in the system. Since reference and data signals propagate through each amplifier, the reference signals used to measure chromatic dispersion receive the same dispersion…
Collimator array
Granted: May 10, 2011
Patent Number:
7940465
A collimator array using a molded element to hold the input fibers and to collimate the light. The input fibers are held within holes in one face of the element, and the collimation of the light emitted from the ends of the fibers is performed by an array of lenses appropriately located such that each lens collimates the light emitted from a fiber end. The lateral spacing between the holes is made to be equal to the lateral spacing between the lenses of the array. Since, in a molded…
Optical switching device with reconfigurable channel spacing
Granted: April 19, 2011
Patent Number:
7929108
An optical switching device includes an array of liquid crystal macropixels, wherein each macropixel includes at least two liquid crystal subpixels. The subpixels may be controlled together to act as a single polarizing pixel, or independently to act as multiple polarizing pixels. When the switching device processes a WDM having a wide channel spacing, the subpixels are controlled together, and when the switching device processes a WDM having a narrow channel spacing, each subpixel is…
Photonic encoder
Granted: April 12, 2011
Patent Number:
7925169
A modulator arrangement for modulating an optical signal using a differential quadrature phase shift key for use in an optical wavelength division multiplex (WDM) optical communications system comprising a laser for producing an optical signal of a selected wavelength, which signal is split by a splitter (4), each part of said split signal being applied to a respective phase modulator (6, 8). The phase modulators (6, 8) are adapted to modulate the phase of the signal in dependence on a…
Packaged optical device stack
Granted: February 22, 2011
Patent Number:
7894722
A packaged stack of optical devices includes two or more WDM optical devices, the stack having a reduced per-channel manufacturing cost and an improved mean time between failure relative to individual optical devices. WDM optical devices, which may be contained in a packaged stack, include wavelength selective switches, optical add-drop multiplexers, and dynamic gain equalizers. The optical switching devices in the stack may be configured so that one or more optical elements are shared…
Method and apparatus for transparent Ethernet multiplexing and demultiplexing
Granted: February 8, 2011
Patent Number:
7885546
A method and apparatus for multiplexing multiple Ethernet-based data streams in an optical network reduce the number of optical transceivers required by the optical network. Multiple data streams are multiplexed into a combined data stream, transmitted from a node in the optical network as the combined data stream, and demultiplexed at the receiving node. Data streams are multiplexed and demultiplexed at the bit level, and packets from each data stream are routed based on a VLAN tag that…
Apparatus and method of coupling a fiber optic device to a laser
Granted: January 11, 2011
Patent Number:
7866897
The present application is directed to a various embodiments of a system for coupling at least one fiber optic device to a laser and include at least one fiber coupler device having a body defining at least one coupling chamber in communication an inlet and an outlet, the coupling chamber sized to receive at least one fiber optic device therein, at least one light stripping element positioned within the coupling chamber, and a housing assembly configured to couple the laser to the fiber…
System of method for dynamic range extension
Granted: December 21, 2010
Patent Number:
7856037
The present invention generally relates to the operation of optical network equipment such as optical amplifiers. In one aspect, a method of operating an optical amplifier is provided such that output of the optical amplifier avoids the effects of operating an optical gain medium in a non-linear (kink) region of an L-I curve. The method generally includes operating an optical gain medium in a fully off state or fully on state above the kink region with a PWM signal. In another aspect,…
Cascaded optical amplifier and control method thereof
Granted: November 30, 2010
Patent Number:
7843630
A cascaded optical amplifier including a first optical amplifier and a second optical amplifier in cascaded arrangement is provided. Each of the first optical amplifier and the second optical amplifier has a respective input for receiving an optical signal, an output for outputting an amplified optical signal, and a control input for controlling the gain of the optical amplifier. The cascaded optical amplifier includes a sensor for sensing upstream of the input of the second optical…
Multiple emitter coupling devices and methods with beam transform system
Granted: November 9, 2010
Patent Number:
7830608
Methods and devices for coupling the output of multiple emitters of a laser diode bar using a beam transform system with high brightness and coupling efficiency. Some embodiments may include wavelength locking with devices such as VBGs and other suitable devices and methods.
Bragg grating reflection strength control
Granted: November 9, 2010
Patent Number:
7830927
A tunable laser comprises a gain section and two or more reflectors. At least one of the reflectors is a Bragg grating comprising a reduced strength section comprising a base order periodic pattern of marks and spaces from at which at least some of the marks or spaces are missing. This enables the reflective strength of the grating to be controlled relative to the other reflector. The Bragg grating may be a phase change grating with individual sections being reduced in strength by line…
Optical channel analyzer with variable filter
Granted: November 2, 2010
Patent Number:
7826055
An optical analyzer (14) for performing spectral analysis on an optical beam (18) includes an optical filter (28), a mover (30), an optical launcher (36), and an optical receiver (38). The optical filter (28) includes a filter area (46) that is a narrow band pass type filter having multiple alternative center bandwidths that are distributed along the filter area (46). The mover (30) moves the optical filter (28). The first optical launcher (36) directs the optical beam (18) at the filter…
Bragg grating structure
Granted: November 2, 2010
Patent Number:
7826508
A Bragg grating has a local reflection strength which varies with position along the length of the grating so as to generate a non-uniform wavelength reflection spectrum, enabling compensation for a non-uniform gain profile of the gain section of a tunable laser. In another aspect, a Bragg comb grating is modulated by an envelope function which can also compensate for a non-uniform gain profile. The comb grating may be a phase change grating, with the envelope function shape being…
Optical wavelength selective router
Granted: October 26, 2010
Patent Number:
7822303
A fiber-optical, wavelength selective switch, especially for channel routing with equalization and blocking applications. The input signals are converted to light beams having predefined polarizations (41). The beams are then laterally expanded (43), and then undergo spatial dispersion in the beam expansion plane. The different wavelength components are directed through a polarization rotation device, pixilated along the wavelength dispersion direction such that each pixel operates on a…
