Digital optical network architecture
Granted: December 15, 2009
Patent Number:
7634195
A digital optical network (DON) is a new approach to low-cost, more compact optical transmitter modules and optical receiver modules for deployment in optical transport networks (OTNs). One important aspect of a digital optical network is the incorporation in these modules of transmitter photonic integrated circuit (TxPIC) chips and receiver photonic integrated circuit (TxPIC) chips in lieu of discrete modulated sources and detector sources with discrete multiplexers or demultiplexers.
Thermo-optic devices providing thermal recirculation
Granted: December 8, 2009
Patent Number:
7630595
Thermo-optical devices providing heater recirculation in an integrated optical device are described. The thermo-optical devices include at least one waveguide having a non-linear path length in thermal communication with a thermal device. Methods of fabrication and use are also disclosed.
Method of reducing insertion loss in a transition region between a plurality of input or output waveguides to a free space coupler region
Granted: December 1, 2009
Patent Number:
7625771
A method for reducing insertion loss in a transition region between a plurality of input or output waveguides to a free space coupler region in a photonic integrated circuit (PIC) includes the steps of forming a passivation layer over the waveguides and region and forming the passivation overlayer such that it monotonically increases in thickness through the transition region to the free space coupler region.
Thermo-optic devices providing thermal recirculation
Granted: December 1, 2009
Patent Number:
7627205
Thermo-optical devices providing heater recirculation in an integrated optical device are described. The thermo-optical devices include at least one waveguide having a non-linear path length in thermal communication with a thermal device. Methods of fabrication and use are also disclosed.
Automated optical link power control
Granted: December 1, 2009
Patent Number:
7627254
A system, apparatus and method are described for controlling the gain across one or more amplifier nodes within an optical span. In one embodiment, a fast local amplifier constant gain control loop is provided that maintains a constant gain across an amplifier node for each of the channels within an optical signal. A slow link level gain setting control loop is provided to set and/or adjust the target gain on the amplifier node(s). A gain adjust sequence is performed by the slow link…
Coupled optical waveguide resonators with heaters for thermo-optic control of wavelength and compound filter shape
Granted: September 1, 2009
Patent Number:
7583879
An integrated optical device is disclosed comprising a substrate, optical waveguide, and compound optical resonator having a temperature sensor, at least two coupled optical resonators, and a heater localized to each optical resonator. An optical input signal is coupled to one of the resonators making up the compound resonator to form an optical output signal. The center wavelength and shape of the output signal is optimized with a feedback loop using the temperature sensor to control…
Low loss lateral optical waveguide intersections
Granted: August 18, 2009
Patent Number:
7577320
A geometrically shaped optical waveguide crossing or intersection with minimal transmission loss is described. A symmetrically tapered waveguide intersection is used to minimize loss in the intersecting region where at least two optical waveguides cross one another at 90° or nearly 90°. The present invention embodies a waveguide crossing that includes tapering the width of the waveguides as they approach the intersecting region, forcing the propagating light to contract, thereby…
Method of fabricating a polarization sorter
Granted: August 18, 2009
Patent Number:
7577325
A method of fabricating a passive polarization sorter includes the steps of providing first and second waveguides. The first waveguide has an input and an output. The first waveguide supporting at least one guided TE polarized mode of mode ranking mode-i-TE and at least one guided TM polarized mode of mode ranking mode-j-TM. The second waveguide is positioned adjacent to the first waveguide, and the first and second waveguides are shaped to form an adiabatic region in which light having…
Pattern-dependent error counts for use in correcting operational parameters in an optical receiver
Granted: August 11, 2009
Patent Number:
7574146
An optical transmission network includes an optical transmitter photonic integrated circuit (TxPIC) chip, utilized in an optical transmitter and has a plurality of monolithic modulated sources integrated for multiple signal channels on the same semiconductor chip is provided with channel equalization at the optical receiver side of the network that permits one or more such integrated modulated sources in the TxPIC chip to be out of specification thereby increasing the chip yield and…
Deployment of electro-optic amplitude varying elements (AVEs) and electro-optic multi-functional elements (MFEs) in photonic integrated circuits (PICs)
Granted: August 4, 2009
Patent Number:
7570845
Electro-optic amplitude varying elements (AVEs) or electro-optic multi-function elements (MFEs) are integrated into signal channels of photonic integrated circuits (PICs) or at the output of such PICs to provide for various optical controlling and monitoring functions. In one case, such PIC signal channels may minimally include a laser source and a modulator (TxPIC) and in another case, may minimally include a photodetector to which channels, in either case, an AVE or an MFE may be…
Method and apparatus for deploying forward error correction in optical transmission networks and the deployment of photonic integrated circuit (PIC) chips with the same
Granted: August 4, 2009
Patent Number:
7570671
An apparatus and method for uniformly sharing across a plurality of channel signals FEC coding gain which may be achieved through FEC encoding of a higher baud rate electrical data signal or through multiplexed or combined electrical data signals from multiple data sources prior to their subsequent demultiplexing and separate generation into optical channel signals which are multiplexed and launched onto an optical transmission medium. The optical signal generation is achieved through…
Symmetric optical circuit with integrated polarization rotator
Granted: July 21, 2009
Patent Number:
7565041
The present invention is directed to an on-chip symmetric optical circuit having one or more integrally fabricated polarization rotators forming a monolithic, solid state polarization independent symmetric circuit. The symmetric optical circuit has at least one integrally fabricated rotator positioned in a plane of symmetry of at least one optical fiber, waveguide or circuit path of the symmetric optical circuit. The folded symmetric optical circuit may be for example a Mach-Zehnder type…
Periodic optical filter
Granted: June 30, 2009
Patent Number:
7555178
A periodic optical filter for interleaving a plurality of optical signals to provide a multiplexed signal for transmission over an optical fiber is disclosed. The periodic optical filter includes a first optical filter constructed to receive at least two optical signals through an input port to provide at least one filtered optical signal. The periodic optical filter also includes a second optical filter, in communication with the first optical filter, constructed to receive the filtered…
Chromatic dispersion compensator (CDC) in a photonic integrated circuit (PIC) chip and method of operation
Granted: June 30, 2009
Patent Number:
7555220
An optical equalizer/dispersion compensator (E/CDC) comprises an input/output for receiving a multiplexed channel signal comprising a plurality of channel signals of different wavelengths. An optical amplifier may be coupled to receive, as an input/output, the multiplexed channel signals which amplifier may be a semiconductor optical amplifier (SOA) or a gain clamped-semiconductor optical amplifier (GC-SOA). A variable optical attenuator (VOA) is coupled to the optical amplifier and a…
Method of monitoring and controlling the bit error rate (BER) in an optical communication network
Granted: June 23, 2009
Patent Number:
7551815
A method is disclosed for monitoring and controlling the bit error rate (BER) in an optical communication network where an optical receiver in the optical transmission network. The method includes the steps of decombining a combined channel signal received from the network and then monitoring a real time bit error rate (BER) of a decombined channel signal. The determined BER is then communicated, such as through an optical service channel (OSC) to an optical transmitter source that is…
Monolithic photonic integrated circuit (PIC) with forward error correction (FEC)
Granted: June 9, 2009
Patent Number:
7546001
Monolithic photonic integrated circuits (PICs) utilize forward error correction (FEC) joint encoder or plural encoders or a joint decoder or plural decoders.
Broadband optical via
Granted: June 9, 2009
Patent Number:
7546007
A broadband optical via provides a low loss interconnection between waveguides in two vertically adjacent planar waveguiding layers. Two waveguides, one in each planar layer, evanescently interact over an interaction length, and substantially all of the power on one waveguide is transferred to the second waveguide. The relative detuning between waveguides is varied along the interaction region by tapering the width of one or both guides along the direction of propagation. The interaction…
Deployment of electro-optic amplitude varying elements (AVEs) and electro-optic multi-functional elements (MFEs) in photonic integrated circuits (PICs)
Granted: May 26, 2009
Patent Number:
7539365
Electro-optic amplitude varying elements (AVEs) or electro-optic multi-function elements (MFEs) are integrated into signal channels of photonic integrated circuits (PICs) or at the output of such PICs to provide for various optical controlling and monitoring functions. In one case, such PIC signal channels may minimally include a laser source and a modulator (TxPIC) and in another case, may minimally include a photodetector to which channels, in either case, an AVE or an MFE may be…
Optical combiner/decombiner with reduced insertion loss
Granted: May 5, 2009
Patent Number:
7529436
A photonic integrated circuit that includes a plurality of active and passive components on a substrate where one of the components is an optical combiner/decombiner having at least one free space coupler region and a plurality of longitudinal ridge waveguides each extending in the circuit from a first region of the waveguide and coupled at a second region of the waveguide at the free space coupler region. A first dielectric layer formed over the ridge waveguides and the free space…
Deployment of electro-optic amplitude varying elements (AVES) and electro-optic multi-functional elements (MFES) in photonic integrated circuits (PICS)
Granted: April 28, 2009
Patent Number:
7526150
Electro-optic amplitude varying elements (AVEs) or electro-optic multi-function elements (MFEs) are integrated into signal channels of photonic integrated circuits (PICs) or at the output of such PICs to provide for various optical controlling and monitoring functions. In one case, such PIC signal channels may minimally include a laser source and a modulator (TxPIC) and in another case, may minimally include a photodetector to which channels, in either case, an AVE or an MFE may be…
