Abstract: A multi-mode optical fiber link is described that includes a single-mode optical fiber having an input that receives an optical signal for transmission through the multi-mode optical fiber link. A first spatial mode converter is coupled to the single-mode optical fiber. The first spatial mode converter conditions a modal profile of the optical signal for propagation through a multi-mode optical fiber. A multi-mode optical fiber is coupled to an output of the first spatial mode converter. A second spatial mode converter is coupled to an output of the multi-mode optical fiber. The second spatial mode converter reduces a number of optical modes in the optical signal. Both the first and the second spatial mode converters increase an effective modal bandwidth of the optical signal propagating through an output of the second spatial mode converter.

Abstract: A multi-mode optical fiber link is described that includes a single-mode optical fiber having an input that receives an optical signal for transmission through the multi-mode optical fiber link. A first spatial mode converter is coupled to the single-mode optical fiber. The first spatial mode converter conditions a modal profile of the optical signal for propagation through a multi-mode optical fiber. A multi-mode optical fiber is coupled to an output of the first spatial mode converter. A second spatial mode converter is coupled to an output of the multi-mode optical fiber. The second spatial mode converter reduces a number of optical modes in the optical signal. Both the first and the second spatial mode converters increase an effective modal bandwidth of the optical signal propagating through an output of the second spatial mode converter.

Abstract: An optical transmitter for an optical fiber transmission system is described. The optical transmitter includes an optical source that generates an optical signal having a wavelength at an output. An optical intensity modulator modulates the optical signal with an electrical modulation signal to generate a modulated optical signal at an output. At least one parameter of the optical intensity modulator is chosen to suppress at least one of phase and sideband information in the modulated optical signal. An optical fiber is coupled to the output of the optical intensity modulator. The suppression of the at least one of the phase and the sideband information in the modulated optical signal increases an effective modal bandwidth of the optical fiber.

Abstract: A multi-mode optical fiber link is described. The multi-mode optical fiber link includes a first spatial mode converter that is coupled to a first single mode optical fiber. The first spatial mode converter conditions a modal profile of an optical signal propagating from the single mode optical fiber to the first spatial mode converter. A multi-mode optical fiber is coupled to the first spatial mode converter. A second spatial mode converter is coupled to an output of the multi-mode optical fiber and to a second single mode optical fiber. The second spatial mode converter reduces a number of optical modes in the optical signal. Both the first and the second spatial mode converters increase an effective modal bandwidth of the optical signal.

Abstract: An optical link is described for transmission of an RF signal using an optical fiber having opposing ends and configured such that unwanted distortion signals are produced when optical signals pass through the optical fiber. At least first and second optical signals are transmitted through the optical fiber, where the optical signals have been modulated with an RF signal in such a way that a predetermined relationship is produced between the RF signals modulated on the first and second optical signals. At the opposing end of the optical fiber, a receiving arrangement receives the modulated first and second optical signals including the unwanted distortion signals produced during the transmission through the optical fiber. The receiving arrangement then regenerates the RF signal from the modulated first and second optical signals while causing the unwanted distortion signals to be canceled based on the predetermined relationship between the RF signals modulated on the first and second optical signals.

Abstract: An integrated optical transmitter for use in an optical system has an optical head assembly with an optical beam generator for providing an optical beam and a lens assembly collecting the optical beam and generating therefrom a formed optical beam. Interface optics receives the formed optical beam and provides optical coupling so as to minimize insertion loss to the optical beam. Also included is an optical modulator for receiving the optical beam from the interface optics and for providing a modulated optical beam in response to received modulation signals. The optical modulator is coupled to the interface optics to be in a fixed relationship therewith.

Abstract: An integrated optical transmitter for use in an optical system includes an optical head assembly having an optical beam generator for providing an optical beam and a lens assembly for collecting the optical beam and generating therefrom a formed optical beam. Interface optics receive the formed optical beam for coupling the beam to a modulator so as to reduce nsertion loss to the optical beam. The optical modulator receives the optical beam from the interface optics and provides a modulated optical beam in response to received modulation signals. The optical modulator is coupled to the interface optics to be in a fixed relationship therewith. The integrated optical transmitter can include a means for sampling the optical beam and controlling the temperature of and/or the current supplied to the optical beam generator for controlling the wavelength of the optical transmitter.

Abstract: A wide dynamic range optical link using a double sideband suppressed carrier linearizer, the link comprising a laser source for producing a lightwave carrier output at a predetermined power level and wavelength, a double sideband suppressed carrier optical modulator having the lightwave carrier as a first input and an RF information-bearing signal as a second input, said double sideband suppressed carrier modulator comprising a signal splitter for dividing the lightwave carrier into primary and secondary carriers, a Mach-Zehnder optical modulator producing a modulated signal comprising information sidebands and a primary carrier component, a feedback controlled phase shifter in which the secondary carrier is shifted 180 degrees from the primary carrier phase, a signal combiner into which are input the modulated signal and the phase shifted secondary carrier, the combination of said signals causing the controlled suppression of the carrier component in the output of the signal combiner.

Abstract: A variable sensitivity compensation network for a Mach-Zender optical modulator comprising first and second pilot signal sources f.sub.1 and f.sub.2, a signal coupler for combining the pilot signals with an RF information signal for modulating a bias-controlled Mach-Zender optical modulator, a variable sensitivity feedback loop comprising an optical detector for detecting the pilot signals from the modulator output, a bandpass filter for selecting the sum frequency f.sub.1 and f.sub.2, a voltage variable attenuator for adjusting the sensitivity of the loop, a logarithmic compression circuit for compressing the f.sub.1 and f.sub.2 signal level from the variable attenuator, means for measuring the signal level, means for controlling the variable attenuator and means for producing an analog bias signal for controlling the operating point of the Mach-Zender modulator. The measuring and controlling means include a microprocessor.

Abstract: A radio frequency pulse multiplier for producing coherent multiples of radio frequency (rf) pulses comprising an input terminal for receiving rf pulses, a signal divider for providing a plurality of pulses in response to an input pulse, the output of the signal divider coupled to a plurality of signal paths, each respective path comprising a time delay element providing a selectable delay to a respective pulse, a signal combiner for combining the plurality of pulses on a single output, and an output terminal. The output of the multiplier comprises pulses delayed by amounts equal to the preselected delays in the respective signal paths of the multiplier. The multiplier may comprise signal conditioning elements for conditioning the rf pulses within the multiplier.

Abstract: A dual-polarization fiber optic communications link comprising a dual polarization light source for emitting a monochromatic lightwave having two polarizations, a polarization splitting coupler for separating the polarizations of the lightwave into a carrier signal and a standard signal, an optical modulator employing the carrier signal and an information signal to produce a double-sideband suppressed carrier signal with the polarization of the carrier, an optical signal combiner for combining the double-sideband suppressed carrier having one polarization with the lightwave standard having a different polarization, said combination occurring substantially without interaction between the respective signals, and the combined signals being coupled to a fiber optic transmission medium. The communications link permits greater modulation dynamic range than conventional amplitude-modulated optical communications links.

Abstract: A thin-film superconducting LC network comprising a dielectric substrate having first and second oppositely disposed surfaces, a first thin-film superconducting conductor on one of the surfaces defining an inductor, second and third thin-film superconducting conductors on said first and second surfaces, respectively, said second and third conductors opposing each other and having at least a portion of the dielectric substrate therebetween to form a capacitor, and thin-film superconducting conductor for interconnecting the inductor and capacitor to form a desired LC network. In one embodiment, the substrate between the second and third conductors have a thickness less than the thickness of the substrate between the first conductor and it oppositely disposed surface. In another embodiment, the inductor is defined by a plurality of closely spaced adjacent turns and a channel is disposed within the substrate between the adjacent turns.

Abstract: A transmission line comprising first and second planar dielectric layers. Each layer has a first surface and a second surface. The first surface of each layer has a plurality of electrical conductors thereon defining a center conductor and at least two other conductors, one on either side of and spaced from the center conductor. The second surface of each layer has an electrically conductive ground plane thereon. The first surface of one layer is opposed to the first surface of the other layer, with the conductors on the first surface of the one layer being in registry with and in physical and electrical contact with the conductors on the first surface of the other layer. A plurality of conductors are provided for making electrical contact with the ground planes and each of the at least two conductors for causing the ground planes and each of the at least two conductors to be at substantially the same electrical potential.