Abstract: A slot waveguide for electro-optic modulation is provided. The slot waveguide includes a slot and Bragg gratings defined by outer walls of the slot. The Bragg gratings are configured to slow an optical signal. The slot defines a low-refractive index region and the Bragg gratings spaced apart by the slot define a high-refractive index region. The slot waveguide includes a pair of electrodes extending parallel and adjacent to the slot waveguide. The electrodes are configured to carry an electrical modulation signal to induce a change in a phase of the optical signal. The slot of the slot waveguide is at least partially filled with an electro-optic polymeric material poled in a direction orthogonal to a direction of propagation of the optical signal in the slot waveguide.

Abstract: A slot waveguide for electro-optic modulation is provided. The slot waveguide includes a slot and Bragg gratings defined by outer walls of the slot. The Bragg gratings are configured to slow an optical signal. The slot defines a low-refractive index region and the Bragg gratings spaced apart by the slot define a high-refractive index region. The slot waveguide includes a pair of electrodes extending parallel and adjacent to the slot waveguide. The electrodes are configured to carry an electrical modulation signal to induce a change in a phase of the optical signal. The slot of the slot waveguide is at least partially filled with an electro-optic polymeric material poled in a direction orthogonal to a direction of propagation of the optical signal in the slot waveguide.

Abstract: The present application is directed an optical gyroscope. The optical gyroscope includes a substrate including a first and a second waveguide disposed thereon. One or both of the waveguides may be doped with a rare-earth material. A crossing element is disposed between the first and the second waveguides to form a substantially orthogonal connection therebetween. The application is also directed to a system including an optical gyroscope. The application is further directed to a method of observing characteristics of the optical gyroscope.

Abstract: The present application is directed an optical gyroscope. The optical gyroscope includes a substrate including a first and a second waveguide disposed thereon. One or both of the waveguides may be doped with a rare-earth material. A crossing element is disposed between the first and the second waveguides to form a substantially orthogonal connection therebetween. The application is also directed to a system including an optical gyroscope. The application is further directed to a method of observing characteristics of the optical gyroscope.

Abstract: An approach is provided that uses diversity to compensate fading of free-space optical (FSO) signals propagating through an environment characterized by atmospheric scintillation. One embodiment involves collecting at least one FSO beam, demultiplexing the beam by wavelength into at least two sub-beams, detecting each sub-beam to produce an electrical output therefrom, and recovering a signal using complementary information from at least two of the electrical outputs. Another embodiment involves collecting the FSO beam onto an array of spatially separated sub-apertures, detecting the light entering each sub-aperture to produce an electrical output therefrom, and recovering a signal using complementary information from at least two of the electrical outputs. This second embodiment enables both electronic adaptive processing to coherently integrate across the sub-apertures and in the case of multiple transmit apertures a free space optical Multiple Input Multiple Output (MIMO) system.

Abstract: A method of beamforming a radiofrequency array having multiple antenna elements is provided. The method includes transmitting two or more sub-beams of a modulated light beam through a switched fabric, using wavelength switching to designate a respective path through the switched fabric for each sub-beam, and converting each sub-beam to a driving signal for one or more of the antenna elements or to a received signal from one or more of the antenna elements. Each path through the switched fabric has a selected cumulative true time delay.

Abstract: A method of beamforming a radiofrequency array having multiple antenna elements is provided. The method includes transmitting two or more sub-beams of a modulated light beam through a switched fabric, using wavelength switching to designate a respective path through the switched fabric for each sub-beam, and converting each sub-beam to a driving signal for one or more of the antenna elements or to a received signal from one or more of the antenna elements. Each path through the switched fabric has a selected cumulative true time delay.

Abstract: An approach is provided that uses diversity to compensate fading of free-space optical (FSO) signals propagating through an environment characterized by atmospheric scintillation. One embodiment involves collecting at least one FSO beam, demultiplexing the beam by wavelength into at least two sub-beams, detecting each sub-beam to produce an electrical output therefrom, and recovering a signal using complementary information from at least two of the electrical outputs. Another embodiment involves collecting the FSO beam onto an array of spatially separated sub-apertures, detecting the light entering each sub-aperture to produce an electrical output therefrom, and recovering a signal using complementary information from at least two of the electrical outputs. This second embodiment enables both electronic adaptive processing to coherently integrate across the sub-apertures and in the case of multiple transmit apertures a free space optical Multiple Input Multiple Output (MIMO) system.

Abstract: In one embodiment, the present invention is a dual-polarized antenna array constructed from first and second instances of a planar antenna that are co-located and orthogonal to one another. The planar antenna comprises three conducting elements and a transmission line. The first conducting element comprises a straight segment and two arms of equal length. The proximal ends of the two arms are attached to opposite ends of the straight segment. The arms extend away from the second and third conducting elements and towards one another. The second and third conducting elements are separated by a gap and together form a mirror image of the first conducting element. The transmission line has first and second conductors that are coupled to the second and third conducting elements, respectively. In another embodiment, the present invention is a tri-polarized antenna array constructed from three orthogonal co-located instances of the planar antenna.

Abstract: In one embodiment, the present invention is a dual-polarized antenna array constructed from first and second instances of a planar antenna that are co-located and orthogonal to one another. The planar antenna comprises three conducting elements and a transmission line. The first conducting element comprises a straight segment and two arms of equal length. The proximal ends of the two arms are attached to opposite ends of the straight segment. The arms extend away from the second and third conducting elements and towards one another. The second and third conducting elements are separated by a gap and together form a mirror image of the first conducting element. The transmission line has first and second conductors that are coupled to the second and third conducting elements, respectively. In another embodiment, the present invention is a tri-polarized antenna array constructed from three orthogonal co-located instances of the planar antenna.

Abstract: A method is provided for increasing the effective transmission range for ones of a plurality of low-power transmitters arranged in an array. In particular, the low-power transmitters are arranged to simultaneously transmit a common information stream, and the transmitters are caused to transmit in a coherent manner. The resultant transmitted energy, as received at a receiver established to receive such transmissions, is thereby increased as a function of the number of operating transmitters.

Abstract: An optical system may be configured as a receiving or as a transmitting system. As a receiving system, it is configured to receive at least one incident laser beam and project the beam into a spot on an array of actuable elements. The position of the spot is determined by the incident angular direction of the beam. The array is configured to track the position of the spot and at each tracked position of the spot to direct the beam onto an actual element. The actuable element tracks the spot so as to direct the beam onto a fixed path toward an optical receiver. As a transmitting system, it includes an actuable element configured to direct the light output from a laser into a spot on an array of actuable elements. The array is configured to track the position of the spot and at each tracked position of the spot to direct the light into a beam-forming system. The beam-forming system is configured to project the light in a transmitted beam having a variable angular direction.

Abstract: A method is provided for increasing the effective transmission range for ones of a plurality of low-power transmitters arranged in an array. In particular, the low-power transmitters are arranged to simultaneously transmit a common information stream, and the transmitters are caused to transmit in a coherent manner. The resultant transmitted energy, as received at a receiver established to receive such transmissions, is thereby increased as a function of the number of operating transmitters.

Abstract: An antenna comprises a resonator and a waveguide. The resonator comprises at least one body having a negative effective electrical permittivity or a negative magnetic permeability when a resonance is excited therein by electromagnetic radiation lying in some portion of the microwave spectrum. A termination of the waveguide is situated adjacent the resonator. The resonator is conformed such that at the resonance, there is efficient coupling between the resonator and the waveguide.

Abstract: An antenna comprises a resonator and a waveguide. The resonator comprises at least one body having a negative effective electrical permittivity or a negative magnetic permeability when a resonance is excited therein by electromagnetic radiation lying in some portion of the microwave spectrum. A termination of the waveguide is situated adjacent the resonator. The resonator is conformed such that at the resonance, there is efficient coupling between the resonator and the waveguide.

Abstract: A process and apparatus is described for recovering from optical transmission degradation due to scintillation effects in optical free space. A payload bit stream is encoded into Reed-Solomon codewords. These are fragmented and distributed as interleaved segments over a cell matrix of a SDRAM buffer store which is made large enough to correct a burst error occurring over 20 million consecutive bits. The rate imbalance between conventional read vs. write operations for SDRAM devices, which would otherwise obviate their use in this application by preventing real time operation, is overcome by an address remapping that avoids having to changing page addresses each time SDRAM memory is referenced. The remapping facilitates a more nearly equal allocation of READ overhead and WRITE overhead. An optical communications system employs at both the transmit and receive ends, substantially equivalent SDRAM buffer with address remapping capability.

Abstract: A process and apparatus is described for recovering from optical transmission degradation due to scintillation effects in optical free space. A payload bit stream is encoded into Reed-Solomon codewords. These are fragmented and distributed as interleaved segments over a cell matrix of a SDRAM buffer store which is made large enough to correct a burst error occurring over 20 million consecutive bits. The rate imbalance between conventional read vs. write operations for SDRAM devices, which would otherwise obviate their use in this application by preventing real time operation, is overcome by an address remapping that avoids having to changing page addresses each time SDRAM memory is referenced. The remapping facilitates a more nearly equal allocation of READ overhead and WRITE overhead. An optical communications system employs at both the transmit and receive ends, substantially equivalent SDRAM buffer with address remapping capability.

Abstract: A method for increasing the interrogation range of an RF Tag in a radio communication system using RF Tags with two reflecting antenna elements. The second reflecting antenna element is predeterminately positioned, and preferably aligned, with respect to the first reflecting antenna element in the direction of expected incident RF radiation and is spaced from the first reflecting antenna element at a predetermined fixed distance. The first and second reflecting antenna elements are alternately pulsed on and off such that while the first reflecting antenna element is in a signal reflecting operating state, the second reflecting antenna element is in a substantially non-reflecting state and vice versa. The alternate pulsing and predetermined fixed spacing between the first and second elements generates a known phase difference between the reflected signals of the first and second reflecting antenna elements.

Abstract: A method for increasing the interrogation range of an RF Tag in a radio communication system using RF Tags with two reflecting antenna elements. The second reflecting antenna element is predeterminately positioned, and preferably aligned, with respect to the first reflecting antenna element in the direction of expected incident RF radiation and is spaced from the first reflecting antenna element at a predetermined fixed distance. The first and second reflecting antenna elements are alternately pulsed on and off such that while the first reflecting antenna element is in a signal reflecting operating state, the second reflecting antenna element is in a substantially non-reflecting state and vice versa. The alternate pulsing and predetermined fixed spacing between the first and second elements generates a known phase difference between the reflected signals of the first and second reflecting antenna elements.

Abstract: A radio communication system includes an Interrogator for generating and transmitting a radio signal. One or more Tags contained within the radio communication system receive the radio signal. A Backscatter Modulator modulates the reflection of the radio signal using a subcarrier signal, thereby forming a reflected modulated signal. The Interrogator receives and demodulates the reflected modulated signal. Based upon the characteristics of the demodulated signal, the Interrogator can determine the identity of the Tag, and the relative velocity of the Tag with respect to the Interrogator. The Interrogator can also determine if motion exists in the vicinity of the Interrogator, even when no Tag is present, without the need for a separate motion detection system. The characteristics of the demodulated signal, can also be used to determine the characteristics of motion of the Tag, such as the vibrational frequency.