Abstract: A high optical efficiency dual spectra pyrometer for measuring the temperature of a target includes an optical guide for collecting and guiding a target optical beam to a detection module which comprises an interference filter and photodetectors adjustably positioned to provide efficient coupling of the target optical beam thereto. The pyrometer additionally includes a signal processor which receives the signals from the photodetectors, as well as signals indicative of an estimated fireball equivalent black body temperature and the spectral width difference between the two detector signals, and provides a compensated temperature signal.

Abstract: A demagnetization compensated magnetostrictive actuator includes a magnetostrictive displacement element and an excitation element responsive to an external signal for providing an applied magnetic field; it further includes a magnetic yoke configuration that encloses both the displacement and excitation elements, for providing a low magnetic reluctance path for the magnetic flux provided by the applied magnetic field.

Abstract: A capacitance pressure measuring circuit includes a pressure sensitive capacitive transducer and a reference capacitor that are configured in a differential mode to alternately charge and discharge in response to square wave signals. An integrator receives signals from the capacitors and outputs two voltage levels. These voltage levels are provided to a synchronous clock driven selectable sample and hold stage and then to a differential amplifier. The amplifier provides a linear voltage signal proportional to the change in the difference in capacitance of the transducer divided by the capacitance of the integrator.

Abstract: A novel test die for emulating the thermal characteristics of functional product dies includes a plurality of concentric emulator ring configurations fabricated about the die center, each having a plurality of heating resistors approximately forming a rectangle, a plurality of sense diodes located in proximity to the heating resistors and a plurality of hot spot resistors located in proximity to both the heating resistors and the sense diodes. Metallic interconnections are formed on the die which selectively provide each of the heating resistors and hot spot resistors with excitation signals and present signals from the sense diodes indicative of the voltage thereacross.

Abstract: A reflection corrected radiosity optical pyrometer includes an optical guide for receiving a target optical beam from a turbine blade in a jet engine. The target optical beam is provided to a detector module that divides the target optical beam into two beams, one having a spectral width selected to be less than the target optical beam spectral width. A signal processor receives signals from the detector module indicative of the energy of the two beams, calculates a reflection corrected energy signal directly therefrom and provides a correct target temperature signal.

Abstract: A microwave infrared modulator having a novel three dimensional structure is presented. The modulator includes a waveguide and metal base with a dielectric wafer buried therebetween. The buried wafer allows for conventional microstrip structures to be employed with larger microstrip electrode dimensions than would otherwise be possible.

Abstract: A novel multiple spot laser welding apparatus includes a bendable mirror capable of deformation, which receives a laser beam at a single reflective surface thereof. A deformation device deforms the single reflective surface of the bendable mirror to provide a plurality of laser sub-beams to a workpiece, generating laser spots on surfaces thereof. The apparatus can be used in a laser welding method that provides a common weld pool formed by laser spots transverse to the weld seam. Another laser welding method provides multiple laser spots oriented along a weld seam producing a common weld pool therebetween. Still another laser welding method provides multiple laser spots along a weld seam producing distinct weld pools.

Abstract: A phase locked ridge waveguide gas laser comprises a plurality of resonators formed in a ceramic body. The resonators are delineated by ridges which provide less than total separation therebetween and allow optical coupling between guided mode optical signals propagating therein.

Abstract: A buried laser mirror used in high energy applications provides discrimination between optical signals of different wavelengths and comprises a ceramic substrate bonded to a faceplate that has a multicomponent reflective interlayer formed on the faceplate inner surface. The multicomponent reflective interlayer provides improved thermomechanical properties while maintaining the mirror's optical integrity and includes a metal reflective layer formed on the faceplate inner surface, a diffusion barrier layer fabricated on the metal reflective layer and a surface wetting layer formed on the diffusion barrier layer.

Abstract: A broadband infrared microwave modulator is fabricated with a thin film electro-optic waveguide mounted to a metal base substrate having a dielectric wafer buried therein to allow high power operation of the modulator.

Abstract: A novel dual spectra optical pyrometer is characterized by a serial array of photodetectors. The first photodetector absorbs a spectral portion of a target optical beam incident thereto, and passes the remainder optical beam to the second photodetector. Signals from both photodetectors are provided along with signals indicative of the first detector's spectral absorption and an estimate of the equivalent black body temperature of a fireball to a signal processor which provides a compensated temperature signal therefrom.

Abstract: An accelerometer includes a cantilevered pieozelectric beam mounted to a surface inside a fluid filled chassis with a proof mass attached to the beam's free end. Surface skimming bulk wave delay lines are mounted on opposing major surfaces of the beam and are responsive to strain induced therein by acceleration of the proof mass.

Abstract: A dual spectra optical pyrometer having an air pressure sensitive shutter for measuring the temperature of a turbine blade includes a sight tube located in the jet engine receiving an optical beam from the turbine blade. Located within the sight tube is a shutter responsive to the jet engine air pressure and providing the turbine blade optical beam only above a selected threshold magnitude of said air pressure. A detection module receives and divides the turbine blade optical beam and provides signals to a signal processor. From these signals and signals indicative of an estimated fireball equivalent black body temperature and the spectral width difference between the two detector signals, the signal processor provides a signal indicative of a compensated turbine blade temperature.

Abstract: A novel dual spectra optical pyrometer for use in in-flight control of jet engines includes an optical probe containing a shutter sensitive to the air pressure within the jet engine. The shutter provides an optical beam from rotating turbine blades to an optical fiber only above a threshold pressure. A serial array of photodetectors receives the optical beam and provides first and second signals therefrom. A signal processor receives the first and second signals as well as signals indicative of the energy ratio therebetween, and provides reflection corrected energy signals from the difference between the first signals and the product of the energy ratio signals and the second signals.

Abstract: A novel cooled mirror for use with high energy lasers includes an optical coating for reflection a laser signal. A heat exchanger having internal passages with flowing coolant is adjacent to the optical coating and removes the heat therefrom. The heat exchanger is affixed to a substrate having supply and return ports for the coolant. The substrate is constructed of porous material so a fraction of the supply coolant bleeds through the substrate to the return coolant. The transpiration flow produces thermal isolation and maximizes the utilization of available coolant heat capacity.

Abstract: An airflow detection system comprising a light source for generating an optical signal that is propagated in an optical guide having a plurality of sensors responsive to the presence of airflow, each of which modulates the intensity of the optical signal at a frequency characteristic of that sensor such that a detection apparatus can receive the optical signal and identify activated sensors using frequency domain multiplexing techniques.

Abstract: A common optical path interferometric gauge comprises an optical beam that is split into two beams. Both beams are modulated and recombined after introducing an optical path length difference greater than the coherence length of the optical source. The combined beam is guided along a common optical path and is subsequently split into reference and measurement beams. The measurement beam is guided along a measurement optical path that includes a moving workpiece surface. Both beams are recombined after interposing an optical path length difference therebetween so as to reestablish coherence between portions thereof, producing optical interference indicative of the surface movement.

Abstract: An optical gauging system comprises a fixture for rotating a workpiece to provide registration of the workpiece surfaces with a measurement optical path and optical interference apparatus for reflecting a measurement optical beam off said surfaces to provide an optical interference signal indicative of the distance between successive surfaces.

Abstract: A linear magnetostrictive actuator with feedback compensation including a force train that has at least one magnetostrictive element, an excitation component disposed on or within the actuator, a feedback apparatus whose output signal is proportional to the magnetic induction within the magnetostrictive element, and actuator control circuitry for providing the difference signal resultant between the feedback output signal and the external signal, such that positional displacement error is compensated by closed loop operation of the actuator.

Abstract: A radio frequency, plasma-enhanced, vapor deposition reactor has apparatus (3-7) for providing a flow of silane in an inert gas carrier, a deposition chamber (20) formed between a pair of flow restrictors (18, 27) and an RF coil (22) for providing inductive coupling of RF power (24) for plasma excitation, disposed downstream of a fixture (8) for holding the substrate upon which amorphous silicon is to be disposed. A baffle (30) provides diversion of the gas flow toward a gravity trap chamber (31), thereby collecting some particulates and prolonging the cycle time before plugging of the vacuum pump (7) can occur.