Abstract: A phase discriminator and data standardizer apparatus measures phase difference between a data signal obtained from a magnetic disk device and a variable-frequency reference data clock. From the measured phase difference, the apparatus develops a phase difference signal used to adjust the frequency of the reference data clock in order to reduce the phase difference. The apparatus includes a multi-state latch circuit that responds to the input data and clock signals by measuring the phase in a phase measurement transition cycle in which only one state variable changes at a time and producing the phase difference signal based upon the measurement. A gate responds to the measurement transition cycle by producing the phase difference signal. The apparatus further standardizes the input data so as to provide the data in a format that is predictably standardized in its time relationship to the reference data clock signal.

Abstract: An optical fiber for transmitting high optical power and of the type having a central core portion adapted to conduct radiation, a cladding layer surrounding the core and at least one covering surrounding the cladding adapted to give an improved mechanical stability to the fiber and to damp scattered radiation wherein, in order to prevent the radiation level in any volume part of the covering from exceeding the limit at which the material of the covering is damaged, the fiber is, at least at its entrance side over a part of its length, provided with radiation resistant and radiation absorbing materials comprising a radiation resistant transmitting material with a real refractive index exceeding or close to that of the cladding, and one, or several, additional material layers of which the outermost are of heat-conducting materials, the radiation being absorbed in the outermost heat-conducting layer(s).

Abstract: A wide band analog frequency divider circuit operable at a high frequency in the GHz band, and a frequency synthesizer utilizing the analog frequency divider circuit. The analog frequency divider circuit comprises an LC series circuit having a capacitor and an inductor connected between the anode and the cathode of a diode, and means for applying a forward bias to the diode. The input signal is supplied from the anode side of the diode, and the output is delivered from the cathode side, or the anode side of the cathode is grounded. The frequency synthesizer is arranged to frequency divide the output of a VCO by the analog frequency divider circuit, and to supply the frequency-divided output to a prescaler. The output of the prescaler is further frequency divided by a programmable divider, and the phase difference between the output of the programmable divider and a reference signal is detected thereby to control the oscillation frequency of the VCO.

Abstract: The present invention provides an improved fiber optic magnetometer having particular application for use in environments having large magnetic field ranges and gradients, such as space based applications. The magnetometer includes a laser which generates a coherent beam of light which is split by a beam splitter into first and second beams. The first beam is passed through a single mode fiber optic having a short metallic conductor attached to it. This fiber is referred to as the "sensor arm" of the magnetometer. The second beam is passed through another single mode fiber which is wrapped around a modulator that is coupled to a feedback circuit. This adjusts the magnetometer such that ambient system noise is filtered and the device is maintained at maximum sensitivity. The output of the two fibers is combined forming a Mach-Zehnder interferometer. A current I is passed through the conductor in the sensor arm.

Abstract: A film thickness measuring apparatus comprising an optical measuring system and an optical projecting system is disclosed. The conventional optical measuring system includes a light source, a first optical system, a monochromator, a second optical system and a photomultiplier tube andmonochromatic light is emitted from the first optical system toward the surface of the film layer on a material of which film thickness is to be measured. While reflection interference takes place between light reflected at the surface of the film layer and light reflected at the base plate, reflected light beam is transmitted to the photomultiplier tube via a semitransparent mirror so that the thickness of the film layer is measured. Before measuring of the film thickness is initiated, there is necessity for determining the correct position of the material to be measured.

Abstract: Method and apparatus for optical inspection of transparent layers such as the wall of glass and plastic containers, using bifurcated fiber optic probes. One or more of such fiber optic probes are directed at the wall of a transparent container, and light emitted thereby is selectively reflected from both the inner and outer surfaces of the container wall. Each probe includes a pair of bifurcated fiber optic bundles which are disposed at different distances behind a 1:1 lens system, resulting in two focal points at different distances from the fiber optic probe. Relative motion of the inner and outer wall surfaces between these focal points results in measurable variations of the probe output signals, which variations may be interpreted to track wall thickness and concentricity. An alternative detection scheme uses a probe with a single bifurcated bundle, and reciprocates such probe relative to the container wall while measuring the separation of null points of the output signal.

Abstract: A battery powered portable test instrument for detecting whether light is propagating in an optical fiber has a jaw into which the fiber is placed, the jaw being closable to press a section of the fiber into a bend having predetermined radius of curvature. If light is propagating through the fiber it is scattered and detected in a detection circuit. If the detected light is greater than the predetermined threshold, an indicator circuit is energized.

Abstract: An optical waveguide device for multiplexing and demultiplexing transverse magnetic (TM) and transverse electric (TE) polarization modes. The device has two waveguides, having first and second coupler segments in close proximity to each other, but with the second coupler segment capable of supporting only one polarization mode. When both TE and TM modes are introduced into the first coupler segment, one mode is coupled completely across to the second coupler segment, but the mode not supported in that segment remains in the first segment and is transmitted to an output port. In the illustrative embodiment of the invention, this selective coupling of the polarization modes is achieved by choosing a narrow width for the second coupling segment, such that the TE polarization mode is not supported but the TM polarization mode is. The interaction length of the coupling segments is selected to produce complete coupling of the TM energy to the second coupling segment.

Abstract: A connector for coupling a medical laser tool to a laser has a housing with coupling fitting at one end which is plugged into a laser receptacle and with a light conductor cable connection at the other end. The light conductor cable in turn is connected to the laser tool. The coupling fitting includes, in addition to the optical coupling element, heavy and light duty electrical contact members for an electrical power and data transmission and a gas conduit coupling for a gas transmission through the connector.

Abstract: A sensing device for use in an adaptive optic system, being provided with an optical phase correcting element, is specifically provided for ascertaining errors in the image of an object as imaged by the adaptive optical system as follows; rod lenses subdivide the entrance pupil of the aperture into a plurality of juxtaposed subapertures having a diameter corresponding to Fried's coherence diameter to obtain a respective plurality of individual images of the object; a high resolution optical-electrical detector array is positioned to receive the plurality of juxtaposed individual images; the relative disposition of the subimages is ascertained under utilization of a correlation computer.

Abstract: An improved film thickness measuring apparatus including an optical measuring system, a detective photomultiplier tube, a corrective photomultiplier tube, a control circuit and a signal processing section. Measuring of the film thickness of a sample material is carried out with the use of spectral reflectivity while optical interference takes place between light beam coming from the surface of the layer structure of the material and light beam coming from the base plate constituting the sample stage. Light beam from light source is introduced into a monochromator to spectrally transform it to monochromatic light. The optical measuring system includes a chopper which serves to chop light beam fed from the light source to introduce intermittent light beam into the monochromator. The latter is provided with a rotatable diffraction grating to effect scanning of wavelength.

Abstract: A photovoltaic relay which includes a unique pull down circuit for rapidly turning off the relays field effect transistor(s). The pull down circuit discharges the gate-to-source capacitance of the relay's field effect transistors by turning on a thyristor by turning off a light-activated switch connected between the gate and the cathode terminals of the thyristor. In one integrated circuit embodiment, the light-activated switch is energized by the same light source which activates the photodiode stack which drives the relay. The presence of the pull down circuit does not effect the turn on time of the relay.

Abstract: A fail-safe laser apparatus includes a laser beam radiation source for emitting a laser beam along an optical axis, a main shutter for intercepting or attenuating the laser beam incident thereon in its closed position, and a safety shutter for completely intercepting the laser beam incident thereon in its closed position. The main shutter is moved to its open position in coagulating the diseased part. A first sensor produces a first signal indicative of the intensity of the laser beam emitted along the optical axis between the radiation source and the main shutter. A second sensor produces a second signal indicative of the intensity of the laser beam emitted along the optical axis between the main shutter and the safety shutter. A detection circuit is responsive to the first and second signals for actuating a safety shutter control means to move the safety shutter to its open position in accordance with the first and second signals.

Abstract: A gas analyzer provided with apertures on the optical paths from a light source through a cell to sensors and multi-layer interference band-pass filters on the respective optical paths. The structure makes it possible to change the distance between each sensor and the corresponding aperture, or the change the size of the aperture, for changing the maximum angle of incidence of light on the filters which is sensed by the sensors to thus change the central wavelength of the filters.

Abstract: The invention is directed to an arrangement for determining the spectral characteristic of the refractive index of a liquid or a gas wherein the specimen is enclosed between two boundary surfaces spaced apart between 1 and 50 .mu.m. The surfaces are at least approximately parallel to each other. The boundary surfaces cause interferences when illuminated with white light passing through the surfaces. The interferences are measured by a spectrometer in their wavelength-dependent course and are thereafter evaluated.

Abstract: An optoelectronic transducer for the conversion of lightwaves to electrical voltage or current, or of voltage or current to lightwaves is disclosed, the transducer comprising a fiber optical system (K, L), a support (T) on which an optoelectronic structural element (D) with at least first and second electric leads (E1/D1, E2/D2/DD) is fastened, and a hole (LO) through the support (T) so arranged that the optically active point of the structural element (D) is directed onto the fiber optical system (K, L) across the hole (LO), the hole wall having a metallic coating (DD) which in operation constitutes a section of the first lead of the structural element (D), the first lead capable of sustaining high speed data transmission.

Abstract: An optical scanning device for mounting in a missile and the like and used for searching for a target. The device is computer controlled with the scanning of the target accomplished with low energy expenditure and great rapidity with uninhibited scanning patterns.

Abstract: A light-reflector type encoding method which comprises emitting light from one end of an optical fiber to a mobile body which moves relatively to said end of the optical fiber, through an optical lattice disposed at a fixed position relatively to said fiber end, receiving the reflected light from at least plural light-reflective graduations provided in the light-emitted zone of said mobile body through the optical lattice, and detecting the received reflected light with a photoelectric conversion element connected to the other end of the optical fiber. The present invention also provides a light-reflective type encoder suitable for carrying out the encoding method.

Abstract: An illumination device is disclosed which includes a lamp for producing light. Light from the lamp enters the input end of a cuboidal integrating bar formed of material having a refractive index greater than .sqroot.2. The edges of the output end of the bar are rendered imperfect by blunting. Light escaping the bar, other than through the output end of the bar, by virtue of the imperfections, is detected by a photosensitive device in a space within a housing around the bar. The housing has inlet and outlet apertures such that light cannot enter the space in the housing other than through the bar. The imperfections are masked so that light cannot enter the bar through the imperfections. The photosensitive device produces a signal indicative of the useful light output of the bar, which signal is not influenced by light entering the output end of the bar.

Abstract: Apparatus for acquiring and demodulating a communication signal employing a feedforward approach to minimize acquisition time. The apparatus includes a phase detection circuit for generating a phase difference signal indicative of the phase difference between an incoming signal and a local reference oscillator, and a phase rotation circuit for adjusting the phase of the local reference by the amount of the phase difference signal, so that the rotated local reference matches the phase of the incoming signal. Basically the same approach is used for carrier acquisition and for data clock acquisition or bit synchronization. A data resolution circuit removes the phase-angle effect of data modulation from the phase error signal, so that an accurate carrier phase error signal is obtained even when the carrier is modulated by data. A special embodiment of the data resolution circuit is provided for the case of non-random data signals.