Abstract: A chemically sensitive device for monitoring chemical properties is described. The device includes a depletion-mode field-effect transistor. Two electrical leads are connected between source and drain region of the field-effect transistor to monitor changes in current or potential resulting from changes in the amount of chemical to be monitored. A reference electrode is attached to a lower substrate surface of the field-effect transistor and electrically connected to the source via a highly doped region adjacent to the source and another highly doped region adjacent to the reference electrode, both having a polarity identical to the substrate. A sensing membrane which is specific to the chemical to be monitored is located on a portion of the substrate remote from the gate region but electrically connected to the gate region to alter conductance between the source and the drain in accordance with the presence or absence of the chemical to be monitored.

Abstract: A signal processor for filtering unwanted narrowband noise from received wideband electrical signals also containing desired wideband noise is described. The signal processor includes means for partitioning the wideband received signal into a plurality of narrowband, noise-containing signals and for producing a plurality of narrowband output signals. The signal processor further includes means for monitoring each of the narrowband output signals and for reducing the voltage of any narrowband output signal when that signal exceeds a predetermined level. In the preferred embodiment, the monitoring means of the signal processor includes a plurality of voltage-regulating networks, wherein each network receives as a network input signal, a single one of said narrowband output signals into a detector and integrator network to produce an output command signal only when the voltage across a channel exceeds a predetermined level.

Abstract: An adjustable coupling device for fiber-optic power dividers in which the coupling characteristics of the divider are influenced by application of transverse forces on the optic fibers in a repeatable fashion. The preferred embodiment consists of a pair of optical fibers which are evanescently coupled by having a portion of each etched to a core and twisted about the other. The etched and twisted portions of these fibers are encased in a rigid housing filled with an elastic filler material. Means are provided for creating forces in the filler material which are transverse to the fibers.

Abstract: The subject invention involves the provision of a cermet for providing relatively high resistivity in a relatively small space. The cermet includes a substrate and multiple, ultra-thin, alternating layers of conductive and nonconductive materials on the substrate. Each ultra-thin layer is formed by radio-frequency sputtering to produce layers of discontinuous islands of particles of each of the above materials. The invention also relates to a method of producing such cermets by radio-frequency sputtering.

Abstract: A technique utilizing either particular software with a microprocessor or computer or a hard wired digital or analog circuit for determining, from a few sample magnitudes acquired from an analog signal at equal time intervals, the shape of the waveform and displaying it. The analog waveform slope at each sample is calculated from the magnitude of the two samples taken from the waveform immediately preceding a given sample and the two immediately following the given sample. A slope of the analog waveform intermediate of each sample interval is then calculated from this information, leading to a final calculation of the magnitude of a selected number of points during the sample interval. The acquired sample magnitudes and the calculated intermediate magnitudes are then combined in a display of a reconstruction of the original analog waveform.

Abstract: An apparatus for maintaining one end of an optical fiber and a focusing lens is provided including means for adjustably focusing a beam of light onto the end of the fiber. The adjustable focusing means includes a means for pivoting the focusing lens and fiber to provide a very fine adjustment to direct the light beam into the core at the end of the optical fiber. The subject device includes a framework for maintaining the lens and one end of the optical fiber in a precisely controlled relationship. The adjustable focusing means may further include at least one screw in threaded engagement with the base portion of the device. One end of the screw contacts a peripheral portion of the maintaining means so that rotation of the screw causes the maintaining means to pivot about the end of the optical fiber.

Abstract: Optical devices having one or more rigidly supported optical fibers and a method of making thereof are provided in which one or more optical fibers are interfaced with a rigid support material by molecular restructuring of interfacing surface areas of the fibers and the support material. The rigidly supported optical fiber may be fabricated by assembling a longitudinal outer surface portion of the fiber in juxtaposition with a rigid support material having a lower melting point than the fiber. This assembly may be heated to allow partial softening of the support material along the outer surface of the fiber to allow fusing therebetween. The assembly may then be cooled below the melting point of the support material to provide a ruggedized fiber-optic assembly comprising an optical fiber fused to a rigid support material. Various optical devices may be formed from combinations of such rigidly supported optical fibers.

Abstract: Optical devices having one or more rigidly supported optical fibers and a method of making thereof are provided in which one or more optical fibers are interfaced with a rigid support material by molecular restructuring of interfacing surface areas of the fibers and the support material. The rigidly supported optical fiber may be fabricated by assembling a longitudinal outer surface portion of the fiber in juxtaposition with a rigid support material having a lower melting point than the fiber. This assembly may be heated to allow partial liquification of the support material and fiber along the outer surface of the fiber to allow fusing therebetween. The assembly may then be cooled below the melting point of the support material to provide a ruggedized fiber-optic assembly comprising an optical fiber fused to a rigid support material. A nonstick mold material also may be provided during assembly which has a substantially higher melting point than either the fiber or the support material.

Abstract: An optical interferometer matrix is described which includes a reference waveguide for optically transmitting a reference signal. The optical interferometer matrix further includes a signal source waveguide for optically transmitting a source signal which has been modulated with respect to the reference signal in response to an applied physical effect. The physical effect may be, for example, thermal, acoustic, hydrodynamic, electrical, electromechanical or magnetic. The reference and signal waveguides are then optically coupled to one another at two different points so that interference between the light in the waveguides occurs under two different phase conditions, with a phase difference between these conditions which approaches .pi./2 radians. In the preferred embodiment, the two points of optical coupling are confined in a small space so that thermal- or pressure-induced differential phase changes of light between the first and second coupling points are negligible.

Abstract: A method and an apparatus is disclosed for making an evanescent wave coupler. Two optical waveguides have a portion of the cladding material removed until the core is exposed. The two optical waveguides are placed in juxtaposition with an interleaf film between them. The interleaf film insures an accurate and constant spatial relation between the two optical waveguides to have reliable evanescent coupling therebetween.

Abstract: An interferometer is disclosed for optically sensing displacements in a surface. A first fiber optic waveguide receives light from a laser in one end and transports it to the other end where a portion is back reflected and a portion is projected upon the surface. The reflected light from the surface re-enters the fiber optic at the projecting end and combines with the back reflected signal to derive an optical information wave. This optical information wave is evanescently coupled to a second fiber optic waveguide which transports this wave to a detector. A specific amount of reflective matter is attached to the end of the first fiber optic waveguide to enhance reflection therefrom, and an optical energy absorber is fixedly attached to the other end of the second fiber optic waveguide to prevent internal back reflection within the second fiber optic waveguide.

Abstract: An optical transducer (10) having a plurality of concentric cores (15,17). An intermediate cladding (16) is disposed between the inner and outer cores and an outer cladding (18) surrounds the outer core to define a symmetrical cylindrical transducer structure. Light propagated through the inner core (15) from a source (19) is coupled into the outer core (17) as a result of penetration of the evanescent electric field from the light in the inner core through the inner cladding (16) to the outer core. Control of the coupling length may be effected by suitable selection of the transducer structure parameters. At least one of the portions of the transducer is formed of an acousto-optically variable material whereby an acoustic field acting on the transducer causes a modulation of the coupled light so as to provide in the outer core (17) a modulated light signal suitable for detection by a receiver (21). Localized control of the parameters of the transducer may be effected to provide focusing of the coupled light.