Abstract: An enhanced output opto-fluidic device includes three plates which together bound a number of passages including an interaction passage, an inlet channel including which opens into one of such ends, and two outlet channels which open into the other end of the interaction passage at symmetrically arranged outlet regions. Fluid is caused to flow through the inlet channel into the interaction passage to form a jet stream that flows toward the outlet regions.

Abstract: Primary logic (116-128) for engine failure detection in a multi-engine aircraft is based on thresholds for engine torque (Q), gas generator speed (NG), power turbine inner stage temperature (T5), power turbine speed (NF), throttle setting (PLA), and throttle manipulation (PLADOT).Subroutines for return to dual engine operation (110), backup of the primary logic (200,300) and remaining engine failure (200) are disclosed.

Abstract: A method of and an arrangement for controlling the operation of a reversible D.C. electric motor including a winding having two ends each of which is connected to both the positive and negative terminals of an electric current source through respective control switches that can be selectively closed and opened in response to command signals to apply voltage differentials across the winding with attendant electric current flow through the winding in one or the opposite direction for operating the electric motor in one or the other of its senses of rotation with intervening rotation sense reversals utilize the original command signals for determining when the sense of rotation reversal would result in an excessive electric current flow through the winding.

Abstract: A positionally adjustable mirror arrangement includes a holding member which is mounted on a support for pivoting about two mutually perpendicular axes. A plurality of circumferentially distributed coarse pivoting actuators pivotally displaces the holding member relative to the support about the two axes within a relatively large angular range. A mirror is mounted on the holding member for pivoting about two mutually perpendicular auxiliary axes. A plurality of circumferentially distributed fine pivoting actuators pivotally moves the mirror member relative to the holding member about the auxiliary axes within a relatively small angular range.

Abstract: An optical fiber has a dielectric periodic index of refraction phase grating established in its core by intense angled application of several transverse beams of ultraviolet light, enabling the establishment of a distributed, spatially resolving optical fiber strain gauge.

Abstract: A distributed, spatially resolving optical fiber strain gauge in which the core of the optical fiber is written with periodic grating patterns effective for transmitting and reflecting light injected into the core. Spectral shifts in the transmitted and reflected light indicate the intensity of strain or temperature variations at positions of the grating corresponding to the associated wavelengths of injected light.

Abstract: A phase-locked staggered ridge array waveguide gas laser includes a body that circumferentially bounds an internal space extending along a central plane and containing a gaseous lasing medium. The gaseous medium is excited at radio frequency with attendant light emission from the gaseous medium. Mirrors are so positioned relative to the body as to provide lasing of the light emission. Two arrays of ridges extending into the internal space along a height dimension partition the internal space into two pluralities of laser resonator cavities each sustaining a guided mode of the lasing light emission. Each of the cavities extends longitudinally of the body and is spaced from an adjacent cavity in a width direction of the internal space.

Abstract: A phase-locked ridge waveguide gas laser includes a body having two major and two minor limiting surfaces together circumferentially bounding an internal space within the body, which contains a gaseous lasing medium. The gaseous medium is excited at radio frequency with attendant light emission from the gaseous medium. Mirrors are so positioned relative to the body as to provide lasing of the light emission. Respective ridges partition the internal space into at least three laser resonator cavities each sustaining a guided mode of the lasing light emission. The ridges extend in an alternative fashion from one and the other of the major surfaces of the body into the internal space and terminate short of the respectively other of the major surfaces to provide respective gaps. Each of these gaps connects two adjacent ones of the laser resonator cavities for phase-locking the guided modes in such cavities.

Abstract: A phase-locked ridge waveguide gas laser includes a body that circumferentially bounds an internal space extending along a central plane and containing a gaseous lasing medium. The gaseous medium is excited at radio frequency with attendant light emission from the gaseous medium. Mirrors are so positioned relative to the body as to provide lasing of the light emission. Respective ridges partition the internal space into a plurality of cylindrical laser resonator cavities each sustaining a guided mode of the lasing light emission. Each of the cavities extends longitudinally of the body and is spaced from an adjacent cavity by a predetermined distance in a width direction of the internal space. The ridges are substantially cusp-shaped and extend into the internal space along a height dimension in respective aligned pairs.

Abstract: An arrangement for detecting the passage of living beings into and out of a surveillance region includes optics which concentrate thermal radiation energy from the surveillance region into a detection zone where an active area of a pyroelectric detector is situated and converts the thermal radiation energy received thereby into an electrical signal. An evaluating device evaluates the electrical signal of the detector to provide an indication of either the entry of a living being from the outside into, or the exit of a person from, the surveillance region from a change in the total thermal radiation energy received by the active area from the surveillance region. The optics may incorporate a mask which prevents thermal radiation from the outside of the surveillance region from reaching the active area of the detector.

Abstract: An arrangement for detecting the passage of living beings through a surveillance region into and out of a controlled-access space includes at least one pyroelectric detector device that includes two detector elements which have active areas that are directly exposed to thermal radiation from the surveillance region and convert the thermal radiation energy received thereby into electrical signals with opposite polaritites. The detector elements are situated in succession in the direction of passage into the controlled-access space. The surveillance region is optically subdivided into two surveillance zones arranged in succession as considered in the passage direction, for instance by a mask that masks an intervening zone situated between the surveillance zones to prevent thermal radiation from the intervening zone from reaching either one of the detector elements.

Abstract: Laser welding is accomplished in a laser welding arrangement by positioning a plurality of workpieces to be joined next to one another so as to form an assembly having at least one interface between the workpieces, by simultaneously directing two laser beams from opposite sides of the assembly against effective welding regions of the workpieces that adjoin the interface and are substantially aligned with one another across the interface, and by effecting relative movement between the assembly and the two laser beams along the interface while maintaining the substantial alignment of the effective welding regions.

Abstract: A compact distributed inductance RF-excited waveguide gas laser arrangement includes a housing which bounds an internal space, and a waveguide laser stack located in the internal space. The stack includes, in succession, a first electrode which may be constituted by a portion of the housing, a waveguide body bounding at least one laser cavity, a second electrode, a spacer body, and a plurality of flat inductor coils that extend along a major surface of the spacer body that faces away from the second electrode and are distributed along the length of the laser cavity. Each of the inductor coils has a first end electrically connected with the first electrode and a second end electrically connected with the second electrode so that, when alternating electric current at radio frequency is applied to one of the electrodes, the inductance of each of the inductor coils is arranged electrically in parallel with the capacitance formed between the first and second electrodes and transversely of the laser cavity.

Abstract: A monitoring arrangement monitors the power of a light beam which travels in a predetermined path between a laser and a destination location and is reflected at a predetermined location of the path from a reflecting surface of a deflecting mirror, with attendant inherent light scattering into a space portion. The monitoring arrangement includes at least one sensor situated in a space portion having the reflecting surface and imaginary extensions thereof for its boundary and including the predetermined path. The sensor is located between a reflected portion of the light beam and the boundary, preferably close to the boundary, to intercept and sense scattered light reaching it, especially forward-scattered light of the original laser beam, and generates a signal representative of the intensity of such intercepted scattered light. This signal is then evaluated.

Abstract: An arrangement for testing a cylindrical object, which may be constituted either by a reflective or refractive element capable of focusing collimated light into a focal line or by an elongated filament, employs cooperation of the element and of the filament, with a laser beam directed onto the element. The filament, especially an optical fiber, extends along the focal line of the element, so that a portion of the laser beam aimed at the element and focused thereby into a waist region extending along the focal line and thus onto the filament, is reflected back to the element and recollimated thereby for travel back along the path of the original laser beam, whereupon the return light beam is caused to interfere with the original laser beam and thus to provide an interferogram that can then be evaluated to obtain information about the magnitude and location of any deviations of the object being tested from its ideal shape.

Abstract: A distributed, spatially resolving optical fiber strain gauge in which the core of the optical fiber is written with periodic grating patterns effective for transmitting and reflecting light injected into the core. Spectral shifts in the transmitted and reflected light indicate the intensity of strain or temperature variations at positions of the grating corresponding to the associated wavelengths of injected light.

Abstract: A compact reflective head-up display incorporating first and second cooperative and converging mirror elements (34,18) one of which has a rear surface reflector (18), and the other of which (34) is partially transmissive and includes a central reflective portion (33), said first converging mirror (34) combining a remote image viewed by a pilot with a display image provided to said first converging mirror (34) by said second converging mirror (18).

Abstract: A bearing arrangement which is to be used for supporting a rotatable shaft used in a system employing a pressurized medium at a pressure which is partially dependent on the speed of rotation of the shaft includes a main bearing sleeve mounted on a support and surrounding the shaft. The working medium is supplied between the shaft and the bearing sleeve to fully support the shaft in the bearing sleeve when the pressure of the working medium exceeds a predetermined value. The bearing arrangement further includes at least one, but possibly more than one, auxiliary bearing including a split bearing ring which has a conical outer circumferential surface and a stationary outer bearing ring surrounding the split bearing ring and having a conical inner ramp surface.

Abstract: A method of establishing a dielectric periodic index of refraction phase grating upon the core of an optical waveguide by intense angled application of several transverse beams of ultraviolet light, enabling the establishment of a distributed, spatially resolving optical fiber strain gauge.

Abstract: An acoustic transducer (10) with a pointed piezoelectric element (11) mounted on an electrically conductive damping mass (12), having a conductive tip (33), the damping mass (12) and conductive tip (33) being electrically connected to opposite terminals in a coaxial line (14). The conductive tip (33) has a convex wear member (35) for contact with a surface to be measured. In one version, the tip (33) is in contact with a flexible conductive sheet (17') for environmental protection.