Abstract:
A system and method for producing a polarization multiplexed signal. The method comprises receiving a first and a second group of electrical data signal, introducing a predetermined delay between the first group of electrical data signal and the second group of electrical data signal and generating a first group and a second group of constant optical signal. The method further includes the electro-optically modulating the first group and second group of constant optical signals using the first group and second group of electrical signals, respectively, and polarization multiplexing the first group and the second group of optical signals together, such that their polarizations are orthogonal to each other.
Abstract:
A method for an optical communication system and an optical communication system comprising a pump source configured to generate a pump signal having rotating polarization, a polarization sensitive receiver for receiving the optical signal having a polarization tracking cut-off frequency, wherein the polarization of the pump signal is configured to rotate at a predetermined frequency of polarization rotation and the frequency of polarization rotation of the pump signal is higher than the polarization tracking cut-off frequency of the receiver. Suitable for mitigation of cross -polarization modulation (XPo1M) related effects in coherent polarization multiplexed quadrature phase shift keying (CP-QPSK) systems.
Abstract:
A high capacity optical transmitter implemented on a photonic integrated circuit chip comprises' a single light source (108) which supplies a continuous wave having a particular wavelength to a plurality of modulators (106,112,126,130) to form modulated optical information signals. A phase shifter (114,128) is coupled to at least one of ' the modulators and' is used to shift the phase of the corresponding modulated optical information signal associated with a particular modulator. A polarization beam combiner (138) receives each of the modulated optical information signals from the modulators and the modulated optical information signal from the phase shifter and combines each of these signals to form a polarization multiplexed differential quadrature phase-shift keying signal. The light source, the plurality of modulators, the phase shifter and the polarization beam combiner are all integrated on the chip.
Abstract:
Embodiments of the present invention provide systems, devices and methods for managing skew within a polarized multi-channel optical transport system. In a DP-QPSK system, skew between polarized channels is compensated within the transport system by adding latency to at least one of the polarized channels. The amount of added latency may depend on various factors including the skew tolerance of the transport system and the amount of skew across the channels without compensation. This latency may be added optically or electrically, and at various locations on a channel signal path within a transport node, such as a terminal transmitter or receiver. Additionally, various embodiments of the invention provide for novel methods of inserting frame alignment bit sequences within the transport frame overhead so that alignment and skew compensation may be more efficiently and accurately performed at the transport receiver.
Abstract:
A communication system includes a multiplexer configured to multiplex a first set of data channels into a first data channel and to multiplex a second set of data channels into a second data channel, and a delay adjuster configured to adjustably delay the first data channel based on a delay adjust command. The communication system also includes a first amplifier configured to amplify the delayed first channel into a first output data channel, and a second amplifier configured to amplify the second data channel into a second output data channel. The communication system further includes a first driver configured to convert the first output data channel into a first drive signal to drive an optical modulator, and a second driver configured to convert the second output data channel into a second drive signal to drive the optical modulator.
Abstract:
The new invention relates to a novel high-performance Passive Optical Network (PON) upgrade architecture, based on adapting Multiple Input, Multiple Output (MIMO) beamforming techniques to polarization multiplexing.
Abstract:
A system and method for increasing channel capacity in fiber optical communication network utilizing space and time modulation. The system utilizes a three dimensional spatial field of time division multiplexing, polarization modulation, and wavelength division multiplexing to increase channel capacity. A plurality of transmitter data processors (10-1, 10-N) receive a plurality of channel inputs for transmission over the optical network. A plurality of optical sources (12-1, 12-N) receive and is directly modulated by the plurality of temporal data streams which are then polarization modulated (14-1, 14-N) before being delivered to a wavelength division multiplexer (16) for transmission over a fiber optics cable (18). The fiber optics cable (18) delivers the wavelengths to a wavelength division demultiplexer (20) for subsequent polarization demodulation (22-1, 22-N), photodetection (24-1, 24-N) of the plurality of temporal data streams which are then delivered to a receiver data processor (26-1, 26-N) for time division demultiplexing of the temporal data. One variation is using an optical cross connect to reuse wavelengths.
Abstract:
Optical transmitter/receivers (1, 250) 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 (106) 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.