Abstract: A method of entangling photons in a distributed quantum-based communication system is disclosed which includes generating sets of entangled photon pairs between a plurality of remote nodes (Nodes Ai and Nodes Bi) and a central entangling node (Node C), wherein Nodes Ai and Bi are in both quantum communication and classical communication with Node C, wherein one photon of a first entangled photon pair set is transmitted Node Ai and one photon of a second entangled photon pair set is transmitted to Node Bi, each over the associated quantum channels, and performing Bell-state measurements between the other photon of the first entangled photon pair and the other photon of the second entangled photon pair, such that if the photons arrive at about same time having about same frequency, then the photon pairs are marked as being entangled.

Abstract: A photon entanglement system is disclosed which includes a plurality of remote nodes (Nodes Ai and Node Bi) each without a quantum memory; and a central entangling node (Node C) in both quantum and classical communication with the remote Nodes configured to provide photon entanglement therebetween, and includes a first and second broadband photon generators each adapted to generate sets of photon pairs at: i) random times within time-bins, and ii) random frequency bins, wherein one photon of each pair set is transmitted to an associated remote node over quantum channels, and a multiplexed Bell-state analyzer configured to receive another photon of the pair, wherein if the received photons arrive at about same time, then the received photons are marked as being entangled by the controller which communicates the associated time-bin to the associated remote nodes and thereby entangling their associated photons.

Abstract: A photon entanglement system is disclosed which includes a plurality of remote nodes (Nodes Ai and Node Bi) each without a quantum memory; and a central entangling node (Node C) in both quantum and classical communication with the remote Nodes configured to provide photon entanglement therebetween, and includes a first and second broadband photon generators each adapted to generate sets of photon pairs at: i) random times within time-bins, and ii) random frequency bins, wherein one photon of each pair set is transmitted to an associated remote node over quantum channels, and a multiplexed Bell-state analyzer configured to receive another photon of the pair, wherein if the received photons arrive at about same time, then the received photons are marked as being entangled by the controller which communicates the associated time-bin to the associated remote nodes and thereby entangling their associated photons.

Abstract: A wireless communication system is disclosed. The system includes a transmitter which includes a data source configured to provide data to be transmitted, a modulator configured to modulate the data, a pre-filter configured to apply a filter to the modulated data generating pre-filtered data, and a transmitter antenna configured to receive the pre-filtered data and to transmit the pre-filtered data, the pre-filter based on a phase compensation topology that is based on channel characteristics between the transmitter and a receiver, the frequency response of the pre-filter based on spectral phase information of the channel such that the frequency response at the receiver is proportional to the magnitude of the channel frequency response.

Abstract: A wireless communication system is disclosed. The system includes a transmitter which includes a data source configured to provide data to be transmitted, a modulator configured to modulate the data, a pre-filter configured to apply a filter to the modulated data generating pre-filtered data, and a transmitter antenna configured to receive the pre-filtered data and to transmit the pre-filtered data, the pre-filter based on a phase compensation topology that is based on channel characteristics between the transmitter and a receiver, the frequency response of the pre-filter based on spectral phase information of the channel such that the frequency response at the receiver is proportional to the magnitude of the channel frequency response.

Abstract: An apparatus and method for correcting for the polarization mode distortion of an optical signal is described. The optical data signal to be transmitted is processed by a switch configured to place the signal into a plurality of polarization states on a periodic basis. At the receiving end of the system, a portion to the signal is coupled to a polarimeter and the wavelength-dependent state of polarization (SOP) of the received signal determined for the plurality of polarization states imposed on the transmitted signal. The data for two of the transmitted polarization states is selected to be used as the basis for correcting the SOP so as to compensate for the wavelength dependence thereof. The corrections may be applied in an optical pulse shaper.

Abstract: An apparatus and method is disclosed for producing and filtering optical and electrical waveforms. The apparatus includes an electro-optical modulator, an optical filter capable of modulating at least two spectral regions within the bandwidth of the electrical waveform, and an optical-to-electrical converter. The optical filter includes a spatial dispersion means, a spatial modulating means having the capability to substantially independently modulate a characteristic of each of a pair of optical spatial elements.

Abstract: A photonic waveform generator and system is described. The photonic waveform generator is used in produce an electrical pulse having arbitrarily controllable temporal characteristics in a Fourier transform (FT) pulse shaper or a direct space-to-time (DST) photonic generator. The electrical pulse signal may be used in a radar, a telecommunications system or other electrical apparatus where the spectral and temporal characteristics of the signal are be optimized with respect to specific system needs, such as spectral occupancy, peak-to-average power, minimum pulse duration, target-to-clutter ratio, target type discrimination, and the like.

Abstract: An optical processing method includes: receiving an optical signal from an optical system, wherein the optical signal is distorted by frequency-dependent polarization effects in the optical system; spatially dispersing frequency components of the distorted optical signal on a spatial light modulator (SLM); and independently adjusting the polarization transfer matrix of multiple regions of the SLM to reduce the distortion of the optical signal. A related optical processing method includes: providing a precompensation signal indicative of frequency-dependent polarization effects in a downstream optical system; spatially dispersing frequency components of an optical signal on a spatial light modulator (SLM); and independently adjusting the polarization transfer matrix of multiple regions of the SLM to at least partially precompensate the optical signal for distortions caused by the frequency-dependent polarization effects in the downstream optical system.

Abstract: An apparatus and method is disclosed for producing and filtering optical and electrical waveforms. The apparatus includes an electro-optical modulator, an optical filter capable of modulating at least two spectral regions within the bandwidth of the electrical waveform, and an optical-to-electrical converter. The optical filter includes a spatial dispersion means, a spatial modulating means having the capability to substantially independently modulate a characteristic of each of a pair of optical spatial elements.

Abstract: An apparatus and method for correcting for the polarization mode distortion of an optical signal is described. The optical data signal to be transmitted is processed by a switch configured to place the signal into a plurality of polarization states on a periodic basis. At the receiving end of the system, a portion to the signal is coupled to a polarimeter and the wavelength-dependent state of polarization (SOP) of the received signal determined for the plurality of polarization states imposed on the transmitted signal. The data for two of the transmitted polarization states is selected to be used as the basis for correcting the SOP so as to compensate for the wavelength dependence thereof. The corrections may be applied in an optical pulse shaper.

Abstract: A short-pulse measurement and detection apparatus utilizing an aperiodic non-linear quasi-phase matched (A-QPM) material. The bandwidth of the A-QPM non-linear material is such that an interaction between a first signal and a second signal occurs, facilitating measurements of signal properties by techniques such as intensity auto-correlation, intensity cross-correlation, and pulse sampling.

Abstract: An optical processing method includes: receiving an optical signal from an optical system, wherein the optical signal is distorted by frequency-dependent polarization effects in the optical system; spatially dispersing frequency components of the distorted optical signal on a spatial light modulator (SLM); and independently adjusting the polarization transfer matrix of multiple regions of the SLM to reduce the distortion of the optical signal. A related optical processing method includes: providing a precompensation signal indicative of frequency-dependent polarization effects in a downstream optical system; spatially dispersing frequency components of an optical signal on a spatial light modulator (SLM); and independently adjusting the polarization transfer matrix of multiple regions of the SLM to at least partially precompensate the optical signal for distortions caused by the frequency-dependent polarization effects in the downstream optical system.

Abstract: An optical processing method includes: receiving an optical signal from an optical system, wherein the optical signal is distorted by frequency-dependent polarization effects in the optical system; spatially dispersing frequency components of the distorted optical signal on a spatial light modulator (SLM); and independently adjusting the polarization transfer matrix of multiple regions of the SLM to reduce the distortion of the optical signal. A related optical processing method includes: providing a precompensation signal indicative of frequency-dependent polarization effects in a downstream optical system; spatially dispersing frequency components of an optical signal on a spatial light modulator (SLM); and independently adjusting the polarization transfer matrix of multiple regions of the SLM to at least partially precompensate the optical signal for distortions caused by the frequency-dependent polarization effects in the downstream optical system.

Abstract: Systems and methods for measuring the state of polarization (SOP) for each wavelength channel in a multi-wavelength-channel light beam are disclosed. The system includes a set of two or more rapidly switchable waveplates switched to form a sequence of secondary light beams having different polarizations. A polarizer filters the set of secondary light beams, and a spectral dispersing element spatially divides the secondary light beams into their respective wavelength components. A detector array measures in parallel the intensity of the different wavelength components for each of the polarization-filtered light beams. A controller stores the intensity measurements and calculates the Stokes parameters for each wavelength component, thereby characterizing the SOP for all the wavelength channels of the multi-wavelength light beam.

Abstract: An optical communications subsystem is proposed to permit the multiplexing of multiple, parallel electronic data streams onto a serial, very high speed optical data channel. The subsystem may also be used to generate programmable ultrafast optical data words for the testing of optical components, and system performance testing of very high speed data transmission systems. The key device component, based on a modified arrayed waveguide grating structure, is directly integratable with a high-speed optoelectronic modulator array in a simple, cost effect, and manufacturable configuration. Pulse spacings as small as 1 picosecond have been demonstrated corresponding to an effective data rate of up to one terahertz. An integrated optical pulse generator is configured to receive a laser light input and output an optical pulse train. Direct space-to-time pulse shaping and optical pulse train generation is achieved by use of an arrayed waveguide (AWG) that is double-passed.

Abstract: Direct space-to-time pulse shaping and optical pulse train generation is achieved in the present invention which features an optical transmitter that includes: an input port receiving a pulsed light beam; a planar modulator coupled to said input port to spatially pattern the beam; a spectral disperser receiving the patterned beam to spectrally disperse and direct the patterned beam; a focus element receiving the dispersed beam and producing a focused beam; and an output port having an aperture positioned to receive a portion of the focused beam.

Abstract: An optical processing method includes: receiving an optical signal from an optical system, wherein the optical signal is distorted by frequency-dependent polarization effects in the optical system; spatially dispersing frequency components of the distorted optical signal on a spatial light modulator (SLM); and independently adjusting the polarization transfer matrix of multiple regions of the SLM to reduce the distortion of the optical signal. A related optical processing method includes: providing a precompensation signal indicative of frequency-dependent polarization effects in a downstream optical system; spatially dispersing frequency components of an optical signal on a spatial light modulator (SLM); and independently adjusting the polarization transfer matrix of multiple regions of the SLM to at least partially precompensate the optical signal for distortions caused by the frequency-dependent polarization effects in the downstream optical system.

Abstract: A liquid-crystal phase modulator array, comprising a planar electrode on one glass support and an array of finger electrodes on the other glass support with a nematic liquid filling the gap between the two supports. The alignment layer between the finger electrodes and the liquid crystal is rubbed to have an alignment direction extending along the finger electrodes and prependicular to the gap between them. The alignment layer between the planar electrode and the liquid crystal is rubbed in the anti-parallel direction. Voltages are selectively applied to different ones of the finger electrodes to provide a phase modulator array for light passing through the assembly. The alignment direction of the invention eliminates ragged edges adjacent the edges of the finger electrodes arising from an instability. Thereby, the finger electrodes can be made much narrower, and more pixels can be included in the array. The phase modulator of the invention can be advantageously used in a Fourier optical pulse shaper.

Abstract: A communications systems is characterized by a pulse-shaping technique for producing shaped, stabilized, ultra-short (picosecond to femtosecond) pulses containing encoded information. Pulse shaping is accomplished by temporally stretching and chirping an ultra-short pulse from a pulse generator, modulating the pulse in real time and temporally compressing the pulse in a manner so as to cancel the original chirp.