Abstract: A Mach-Zehnder interferometer has electrodes configured to act as a microe transmission line. The optical waveguide arms have a reflective coating on their distal ends so that light is reflected back through the arms. The microwave transmission line is open-ended in a vicinity of the reflective coating so that microwave energy is reflected at the open end. Thus, the interferometer supports a traveling wave in a reflective configuration, and the distance over which interaction takes place can be effectively doubled.

Abstract: This invention is a demultuplexer consisting on a sequential division of the data stream in a series of Sagnac interferometer amplitude modulators (SIAMs), wherein each modulator in the series is driven by a single microwave frequency derived directly from a radio frequency (RF) data rate clock, with the RF phase properly adjusted to extract a channel of interest.

Abstract: An optical intensity modulator which uses a Sagnac interferometer having an electro-optic phase modulator therein. An electric modulation signal is delivered to the modulator, and the latter is selected so that the phase velocity of optical and electrical signals are comparable in it. This causes the optical signal from one interferometer arm to copropagate through the modulator with the electrical signal, increasing interaction time with it, and causes the optical signal from the other arm to counterpropagate with the electric signal, reducing interaction time. In addition to phase modulating the optical signals by the electrical signal, the electro-optic effect in the modulator phase shifts the optical signals with respect to one another, permitting them to form a non-zero interference pattern, whose intensity corresponds to the electrical signal.

Abstract: The wavelength multiplexed, electro-optically controllable, fiber optic multi-tap delay line utilizes a first output signal from a plurality of amplitude adjustable continuous-wave (CW) optical lasers multiplexed to form a combined optical signal onto which a radio frequency signal is imposed thereby shifting the combined optical signal which is then demultiplexed. A second output signal of the plurality of CW lasers is phase adjusted and combined with the demultiplexed combined optical signal to form a RF phase adjusted modulated optical signal. The plurality of phase adjusted modulated optical signals pass through associated optical delay lines and are multiplexed to form a single optical signal containing a plurality of optical channels having different characteristics which is applied to a detector to produce an output electrical signal for transmission to using devices.

Abstract: Underplating between a metallic plating base and a photoresist deposited reon can be reduced or eliminated by a method of fabricating a microstructure which includes the steps of:(a) depositing a plating base on the adhesion layer;(b) depositing on the plating base a sacrificial layer of a material that reduces or eliminates underplating on the plating base compared to underplating in absence of the sacrificial layer;(c) depositing a photoresist on the sacrificial layer;(d) exposing, developing and removing the exposed photoresist from the substrate to uncover a portion of the sacrificial layer;(e) removing the sacrificial layer portion from the substrate to uncover a portion of the plating base; and(f) depositing a metallic material on the uncovered plating base under the influence of electrical current.

Abstract: An optical link is disclosed that is operated by a balanced detection technique so as to extend its linear dynamic range, yet substantially eliminate even-order harmonic distortion of the modulated signal. The modulator comprises two parallel arranged Mach-Zehnder interferometers that respectively have a steady state DC voltage bias applied so that the operating points of the Mach-Zehnder interferometers are selected to produce two separate modulated signals, one of which is later phase shifted by a phase shift device so as to provide an output that is combined with the other modulated signal in such a manner so as to cause a subtraction, leaving the final output signal substantially free of any unwanted even-order harmonic components in order to provide for a multi-octave response characteristic.

Abstract: A transmission system responsive to an electrical input information signal ncludes means for modulating the input signal with a microwave subcarrier signal to produce a subcarrier modulated signal. A first interferometric modulator responsive to a source light and to the subcarrier modulated signal produces a first modulated optical signal. A second interferometric modulator cascade coupled to the first modulator and being responsive to the first modulated optical signal and to a microwave local oscillator signal produces a second modulated optical signal. Means coupled between the first and second modulators transmit the first modulated optical signal from the first modulator to the second modulator. Means responsive to the second modulated optical signal produce an output signal.

Abstract: A method and apparatus for counteracting polarization fading and stimulated Brillouin scattering in long runs of non-polarization maintaining optical fiber. A linearly polarized optical signal is depolarized by phase modulating the signal at a frequency significantly above the fiber's Brillouin scattering linewidth V.sub.b prior to launch into the long run of fiber.

Abstract: An electro-optic mixer includes means for providing first and second microwave signals having first and second frequencies, respectively, a device for providing a source light, a first modulator responsive to the source light and to the first microwave signal for producing a first modulated optical signal, a second modulator cascade coupled to the first modulator and being responsive to the first modulated signal and to the second microwave signal for producing a second modulated optical signal having a frequency component at the sum or difference or both of the first and second frequencies, and means coupled between the first and second modulators for transmitting the first modulated signal to the second modulator.

Abstract: A process for making thick metal structures on a substrate has the steps of: selectively exposing a thick layer of photoresist disposed on a substrate to ultraviolet radiation including the 350 nm to 450 nm portion of tile spectrum of a mercury vapor lamp, where the photoresist layer is a heat-treated arid hydrated photoresist layer, to fully pattern the substrate: developing the patterned substrate by contacting the photoresist layer with a photoresist developing solution; exposing the photoresist layer to a plasma for hardening the pattern against thermal flow; hardbaking the photoresist pattern on the substrate; plating the metal onto the patterned substrate using a low current density (J) during at least part of the plating process, making a thick methyl structure on the substrate.

Abstract: A system and method for subtracting excess noise from a high sensitivity gyroscope system in which a laser diode array is focused into an Nd-doped active fiber. A resultant gyro signal is polarized, detected, and amplified. A noise signal is polarized, delayed, detected, and amplified such that the noise signal is polarized parallel to the gyro signal and delayed by a fiber delay, of a length equal to a length of a gyroscope fiber coil. The excess noise component in the amplified gyro signal is reduced by modulating the amplified noise signal with a portion of the amplified gyro signal and subtracting the amplitude-modulated noise signal from the amplified gyro signal to produce a reduced noise gyro signal.

Abstract: A fiber superfluorescent light source is disclosed which suppresses laser cillations without interfering with the pump light or the super luminescence. In a preferred embodiment of the invention, the fiber superfluorescent light source comprises a laser diode array for providing a pump beam at a wavelength of 0.81 microns, a first fiber doped with neodymium activator ions and being responsive to the pump beam for providing a spontaneous emission at a wavelength of 1.06 microns, and a second fiber optically coupled between the laser diode array and the first fiber for passing the pump beam therethrough to the first fiber to enable the first fiber to spontaneously emit light at the 1.06 micron wavelength and for suppressing backemissions of the 1.06 micron wavelength from the first fiber toward the laser diode array to prevent back reflection from the laser diode array and oscillations in the first fiber.

Abstract: A depolarized fiber optic gyroscope with a detector for detecting a rotat about an axis of rotation and a method therefor is disclosed. The gyroscope includes a depolarized light source for generating the depolarized light; a gyro coil for conducting depolarized light about the axis of rotation, the gyro coil including a coil of a non-polarization preserving fiber having first and second ends; a depolarizer with first and second ports for eliminating birefringence induced scale factor variations caused by the non-polarization preserving fiber, the first port of the depolarizer being coupled to the first end of the gyro coil; and a coupler device for coupling the second end of the gyro coil, the second port of the depolarizer, the detector and the depolarized light source, without utilizing a polarizer.

Abstract: An apparatus comprised of a depolarized light source for fiber optic sensors is disclosed. In a preferred embodiment, the depolarized light source of the apparatus comprises: a first laser for generating a first beam at a first frequency, the first beam having a linear polarization state; a second laser for generating a second beam at a second frequency, the second beam having a linear polarization state; a means for rotating the polarization state of the second beam so that the first and second beams have orthogonal linear polarization states with respect to each other; and a means for combining the first beam with the polarization-rotated second beam to obtain a composite beam which is depolarized.

Abstract: The manufacture of an optical waveguide device utilizing a fast, accurate method for tuning of the output phase angle of such devices to a desired operating point. Tuning is accomplished by adjusting the accumulated phase along a waveguide arm of the device by removing optical waveguide material using laser ablation. Due to the change in waveguide geometry in the ablated region, the optical phase velocity is changed and thus the optical path length is affected in that section of waveguide, thereby resulting in a change in output phase angle.

Abstract: The manufacture of an optical waveguide device utilizing a fast, accurate method for tuning of the output phase angle of such devices to a desired operating point. Tuning is accomplished by adjusting the accumulated phase along a waveguide arm of the device by removing optical waveguide material using laser ablation. Due to the change in waveguide geometry in the ablated region, the optical phase velocity is changed and thus the optical path length is affected in that section of waveguide, thereby resulting in a change in output phase angle.

Abstract: An apparatus for generating a relatively high-power, modulated optical beam s disclosed. The apparatus comprises a first element for emitting a relatively low-power laser beam at a preselected wavelength, means for focusing the laser beam into a focused beam, a damage-resistant integrated optic modulator responsive to the focused beam for developing a modulated beam, optical means for shaping the modulated beam into a shaped modulated beam, and semiconductor means having a large active area responsive to the shaped, modulated beam for producing a relatively high-power, output modulated beam. In a first embodiment, the semiconductor means is a semiconductor amplifier which amplifies the modulated beam to produce the high-power, modulated output beam.

Abstract: An optical transversal filter comprises a plurality of optically power spting devices, e.g., 3.times.3 single mode optical couplers, interspersed with fiber optical delay segments. In a n-column system the number of optical couplers in each column is given by the progression, 1,3,9 . . . 3.sup.(n-1) and only two different lengths of the fiberoptic delay segments are required. Fiber optic delay segments of the appropriate delays are connected to the three outputs of each of the composite such that the fiber optic delay segments connected to the last column provide 3.sup.n taps. The outputs can be combined in a single fiber and multiple inputs can be used. Variable weight output taps are provided by connecting each output to an optical intensity modulator or switch.

Abstract: An apparatus and method are disclosed for optimizing the modulation efficcy of a remotely-located, polarization-sensitive, integrated optic modulator which is addressed with a non-polarization preserving fiber link. In a preferred embodiment of the invention, the polarization state of an input light beam is changed as a function of first and second control signals that are applied to the polarization controller. The non-polarization preserving fiber link conveys the light beam with the changed polarization state to the integrated optic modulator. The integrated optic modulator modulates the light beam with the changed polarization state as a function of any information signal to develop an intensity modulated optical signal. If no information signal is present, the optical signal from the modulator is not modulated. An output fiber conveys the optical signal from the integrated optic modulator to a locally-positioned detector for detection.

Abstract: Successive waveguide regions in a birefringent waveguide host electric fields oriented transverse to any optical wave propagated through the waveguide. A scheme of cascaded electrodes biased by voltage(s) applied to the electrodes dictate instantaneous field polarity. Cascaded electrodes are sited in nonopposed, noninterleaved relation on opposite sides of a long electrode partially overlapping the waveguide.