Abstract: Pressure or strain sensitive optical fiber having a core, at least a portion of which has a predetermined refractive index for transmitting light therethrough, a cladding adjacent the core having a refractive index which is less than that of the core, and a concentric light transmissive layer adjacent the cladding having a refractive index which is greater than that of the cladding. The light transmissive layer has an internal diameter which is greater than the unperturbed mode boundary diameter of the core, such that all light passes through the core when the fiber is unperturbed. When the optical fiber is subjected to pressure forces in the form of stress or strain, light passes through the light transmissive layer in proportion to the amount of stress or strain acting upon the fiber. Also, pressor sensors and methods for measuring forces or pertubations utilizing such optical fiber.

Abstract: A voltage controlled oscillator circuit of a type having a tank circuit for generating oscillations which includes a means for establishing a fixed bias voltage with respect to ground at a bias end of said tank circuit, means for drawing current from an a.c. end of said tank so as to control the tank gain, and an AGC capacitor. A constant current source is coupled to the AGC capacitor for supplying it with a constant charging current. Means are provided for discharging the AGC capacitor at a voltage level determined by a ratio of resistors and a transistor emitter-base ratio.

Abstract: In an electrochromatic, transparent layer system comprising at least one electrochromatic layer (2), two electrodes (3, 5) separated by a hydrogen ion supplying layer which simultaneously is a hydrogen ion storing layer (4), there is located, seen in the direction of light incidence through the layer system, a further hydrogen ion conducting layer (6) (e.g. of SiO.sub.2) behind the electrode (5), behind which a further electrode (7) is arranged. The electrode (7) is capable of oxidizing hydrogen diffusing from within the system into hydrogen ions. For this purpose, a protective voltage is applied between electrode (5) and electrode (7) such that the third electrode (7) forms the positive pole.

Abstract: An optical connector includes a plug and an adaptor to which the plug is to be connected. The adaptor is formed with a plug body fitting portion and a holder fitting portion. The plug has a plug body to which a optical fiber cable is fixed. A floating holder is arranged in the plug body to be movable in any direction with respect to the plug body. An end of the optical fiber of the cable is attached to a ferrule which is supported by the holder. When the plug is connected to the adaptor, the plug body is fitted to the plug body fitting portion and the holder to the holder fitting portion. At this time, the plug body is locked to the plug body fitting portion by a lock mechanism, and the holder is locked to the holder fitting portion by engaging projections on the holder and engaging holes which are formed in the holder fitting portion and engaged with the projections.

Abstract: A single-mode electro-optic switch (10 or 10') including a graded index layer (14b or 14b'). Two electro-optic embodiments are disclosed. The first embodiment includes a substrate (12) and a planar waveguide (14) atop the substrate (12) including a graded index layer (14b) sandwiched between a pair of lower refractive index layers (14a and b 14c). The substrate (12) preferably forms anisotropically etched V-grooves (38) suitable for receiving fibers (50) and (52) and for registering the cores of the fibers with the middle layer (14b). The first embodiment of the switch includes a single input port and a pair of output ports, wherein when the switch is energized, light is reflected away from the first output port and toward the second output port.

Abstract: A reticle design is provided for step and repeat projection aligners which, when patterned on a wafer (10), allows quick macroscopic evaluation of best focus for used in fabricating integrated circuits. The reticle pattern consists of opaque lines and spaces of widths slightly above the resolution limit of the resist/aligner system. The macroscopic determination of best focus, being macroscopically visible, eliminates the need for microscopic determination, thereby providing a quick and easy method. The best focus determination is made by forming an array (22) of resist fields (14') on the wafer, subjecting each field to a different focus and exposure. Upon development, those fields away from the best focus and at the larger exposure doses will be removed, leaving a parabola (24) of fields whose apex (26) is at high exposure. Best focus is the focus setting used to print the row of fields (B) containing the apex.

Abstract: An internally matched power amplifier including an input terminal for receiving an input signal and an output terminal; a plurality of semiconductor devices connected with the load electrodes in series; transmission means for coupling the load electrodes of neighboring devices in the series and establishing an internal impedance match; the last device in the series having its other electrode connected to the output terminal; the first device in the series having its control electrode connected to the input terminal and its other load electrode connected to a common conductor and having a predetermined d.c. bias level and a predetermined signal voltage level between its control and its other electrode; first means for setting the control means of each device but the first in the series to the predetermined signal voltage level and second means for biasing the control electrode of each device but the first in the series to the predetermined d.c. bias level.

Abstract: An optical multiconductor of the silica glass type characterized in that the multiconductor comprises 10.sup.2 to 10.sup.7 optical fibers of the silica glass type fused to one another, each of the optical fibers comprising a core made of doped silica glass and occupying at least 20% of the fiber in cross sectional area, and a cladding layer made of a kind of silica glass and formed on the core, the core having a refractive index distribution satisfying the following expression:n2.gtoreq.n1+0.50(n0-n1)wherein n0 is the refractive index of the core at its center, n1 is the refractive index of the core at its outermost portion, and n2 is the refractive index of the core at a position centered about the axis of the core and having an average radius of 0.65r1, the r1 being an average radius of the core.The multiconductor is suited to use as the image transmitter of an image scope for industrial, medical or other uses.

Abstract: A combination pattern-refraction modification type phase grating comprises dual grating elements which are regularly arranged and each includes convex and concave portions which have respectively different thickness and are formed of material respectively different in refractive index so as to combine respective characteristics of a pattern and a refraction modification type phase grating.

Abstract: An amplifier for ground symmetrical signals includes a compressor at the input and an expander at the output, with the slope of at least one of its expansion or compression characteristics being adjustable for at least one half-wave polarity with the aid of an adjustment voltage. In order to reduce second order distortions at the amplifier output, a circuit is provided for determining the arithmetic mean value of the voltage across the amplifier output. A control value is produced from the determined mean value and the slope of the expansion or compression characteristic is regulated with this control value in the opposite direction so that the distortions are reduced.

Abstract: Light generated in the optical resonator of a gas laser is polarized by disposing an array of fine, parallel, highly light reflective wires in the path of the light beam propagating in the resonator. The wires are cooled by conduction of heat to a heat sink or by causing gas to flow through the array. In one embodiment, the wire array is arranged to be rotated to enable the plane of polarization to be turned to any desired orientation. The difference in absorption by the wire array between two orthogonal components of the flux in the resonator need be only in the order of 1% to cause nearly complete linear polarization of the light emerging from the resonator. The parallel wires, preferably, are spaced so that they are situated at the peaks of the lower order modes in the resonator. In lieu of using fine wires, very fine parallel lines or grooves whose width and spacing are such as to provide a low efficiency diffraction grating may be provided in the surface of an optical element of the resonator.

Abstract: Feedforward of the source signal into the compensation mode of an operational amplifier produces more than an order of magnitude improvement in small-signal capability at high frequencies. The technique is useful for active filters and wideband amplifiers. Further improvement will be available using amplifiers designed for this approach.

Abstract: An RF amplifier wherein an IREB interacts with RF energy from an RF energy source coupled via an RF cavity to a tube drift region where the IREB is modulated at the frequency of the RF energy source, to provide high gain amplification at high power and high efficiency.

Abstract: The inventive method for forming monolithic nonlinear Fabry-Perot etalons comprises depositing on an appropriate substrate, e.g., a GaAs wafer, a first multilayer mirror, depositing on the first mirror a spacer typically comprising optically nonlinear material, and depositing a second multilayer mirror onto the spacer. Typically, at least one of the mirrors is an active mirror comprising optically nonlinear material. Deposition can be by a known process, e.g., by MBE or MOCVD. Since, inter alia, the method comprises no critical etching steps it can be used to produce high finesse etalons that have uniform properties over relatively large areas. The inventive method can be adapted to the manufacture of transmissive etalons. It can also be used to produce arrays of optically isolated etalons. Devices comprising nonlinear etalons manufactured by the inventive method can be incorporated, for instance, into optical data processing apparatus, or into optical communications apparatus.

Abstract: A demodulator for regenerating and demodulating a carrier signal from a four-phase PSK received signal having a data symbol preamble and a fixed phase (one of four phases) of a particular time width using a synchronous detection type demodulating system (remodulation type demodulating system). The demodulator includes an orthogonal demodulating circuit and a remodulating circuit for regenerating a carrier signal which is the data signal during a preamble transmission period from a received modulated signal. The remodulating circuit includes a demodulator having an AFC circuit for detecting a frequency change using a narrow band filter, means for suppressing frequency changes of the four-phase PSK modulated signal received and means for rendering constant the frequency of the regenerated carrier signal passing through the narrow band filter.

Abstract: Herein disclosed are an amplifier and a display which uses the former. The amplifier includes a current amplifying circuit for sending out an amplified output current varying according to an input signal, and a current-voltage converting circuit for converting the output current of the current amplifying circuit into a voltage thereby to generate a high output voltage in response to the input signal. The supply voltage V.sub.cc1 of the current amplifying means and the supply voltage V.sub.cc2 of the current-voltage converting means are set separately of each other to have a relationship of V.sub.cc1 <V.sub.cc2. Thus, a high output voltage can be obtained from the current-voltage converting circuit without the need for the current amplifying means to have high breakdown voltage elements.

Abstract: In the disclosed automatic focus detecting device for an imaging optical system a light spot is projected onto an object and an image of the object is formed on a predetermined focal plane. A light receiving photo-sensitive element produces at least two signals according to the position of the reflection of the projected light spot. A comparator detects when the relation between the integrated values of outputs of the light receiving element exceeds a predetermined level. A detector means detects when the light spot image has been projected for a predetermined time and a determining arrangement determines the focus of the imaging optical system on the basis of the outputs of the light receiving element when at least either the comparator or time detector detects the predetermined level or length of time.

Abstract: Method of determining stereoscopic geometry of an object through photometric stereoscopic measurement with high accuracy. Three or more images of the object picked up in a same fixed direction by varying the state of light sources are derived. Relationships among the images are corrected so that an evaluation function determined by making use of redundancy of the images assumes a minimum value, to thereby prepare a reflectance map to be used in determining orientations of surface elements of the object. Through integration of the orientations, the surface shape of the object is determined. The method is applicable to the image processing in a scanning electron microscope.

Abstract: The process utilizes the fact that fluorescent optical fibres can be laterally excited by light radiation by supplying concentrated light signals to their ends. The invention proposes applying this process to producing indicating, control, logic function measurement and similar apparatus, as well as for producing solar collectors for the direct generation of electricity.

Abstract: An amplification gain adjusting circuit in which the gain of an AC amplifier is controlled by a voltage dividing series connection of two resistors. One of the resistors is selectively shorted by a switching transistor. The DC bias of the switching transistor is set to prevent current flow through the base of the switching transistor at high AC levels.