Abstract: An improved optically coupled isolator uses a glass layer in combination with layers of junction coat material between the emitter and detector to provide greater electrical isolation while preventing potential ionic contamination in the glass from reaching the detector and causing a deterioration in its operating characteristics. The isolator is assembled using standard semiconductor processing techniques so that the cost of manufacture is not substantially increased.

Abstract: An optical fiber is hermetically sealed to a metal housing containing an optical device (e.g, a semiconductor junction laser or photodiode) by threading and centering the fiber through a thin walled metal tube, filling the tube with solder (e.g., a cylindrical preform) and allowing it to cool. The solder, upon solidifying and cooling, squeezes against the fiber and forms a hermetic seal. The tube-fiber assembly is inserted through an aperture in the housing wall, the fiber is aligned with the optical device and then the tube is soldered to the wall. The housing is out-gassed and then back-filled with a noncorrosive ambient such as nitrogen. Other aspects of the hermetic package, including a laser mount, are also described.

Abstract: An optical coupler is provided for connecting between optical fibers and electro-optical elements in optical communication systems. The coupler comprises one element consisting of a connector fiber within a support tube fixedly attached to the electro-optical elements at one end and optically polished at the other end. Connection between the connector fiber and an optical communication fiber is provided by means of a second element consisting of a dual diameter connector tube. The dual diameter tube slidingly engages the support tube at one end and the systems fiber at an opposite end to provided close optical proximity between the systems fiber and the connector fiber.

Abstract: An optical coupling includes a socket, in which an electro-optical element is mounted, and a plug, in which a light-conducting element is fastened. The plug mateably engages the socket in such a manner that the electro-optical element and the light-conducting element are optically connected. The electro-optical element is removeably and axially adjustably mounted in the socket so that the electro-optical element can be replaced and optimum focusing and light-transmitting efficiency can be attained.

Abstract: A coaxial reflex photoelectric scanner comprising first and second lenses, a photoelectric light source and a photodetection device, all mounted within a housing in coaxial relationship with one another. The photodetection device is positioned between the light source and the second lens, wherein the second lens is positioned between the photodetection device and the first lens. The second lens is so positioned that the photodetection device absorbs an optimum quantity of light energy that is reflected back from an object and through the first and second lenses.

Abstract: An apparatus including a frusto-conically shaped tube for transmitting light with internal reflection surfaces which diverge in the direction from input to output. Incident light from an LED or other substantially phase coherent source is mixed by internal reflection of rays incident at greater than a predetermined angle to minimize the non-uniform phase front and concentrate the beam to permit greater transmitted power. The apparatus finds particular utility in distance measuring instruments in which the output of the tube is directed to an object and the phase of the reflected light compared with the phase of the transmitted light to determine the distance.

Abstract: Vehicle control system of the retro-reflective, pattern-coding type in which the signal device is carried on the vehicle and the scanner and controls are carried beneath the supporting surface.

Abstract: A motion picture sound reading system employing a light emitting diode source which is modulated at a carrier frequency several times higher than the highest sound-track frequency for exciting the optical sound track and a carrier-demodulation signal processing system for deriving a high-quality audio signal from the photoelectrically detected optical sound track.

Abstract: A control circuit for maintaining the sensitivity of an avalanche diode at an optimum is shown. Such diode, when used as a photosensitive detector in a receiver in an optical radar, is biased by the disclosed control circuit so that the frequency at which internally generated noise impulses are generated is maintained at a predetermined rate so that echo signals may be distinguished from such impulses.

Abstract: An optoelectronic device comprising a light-sensitive device which produces or modifies an electric current in dependence upon the intensity of light incident thereon, and a light-emitting device arranged to emit light in response to said electric current and so disposed that part of said emitted light is incident upon the light-sensitive device to provide positive feedback.

Abstract: Smoke detector apparatus characterized in the utilization of solid state components in conjunction with standard primary batteries as a power source. Operating under photo-optical principles, the apparatus incorporates a solid state detector which, while having a low current drain characteristic, exhibits dark current phenomena. A stabilization network is provided to accommodate for this phenomena which includes an amplifier having a transistor stage and means for clamping that stage in a partially forwardly biased state. Detection of smoke causes the amplifier to generate a signal output as a step function.

Abstract: A photoelectric sensing system for detecting the occurrence of interruptions of a light beam is arranged to compensate for non-interrupting short-term variations occurring during transmission of the light beam. A clock controlled memory element enables a light emitting generator to generate a serial train of light pulse signals. Each generated light pulse signal is sensed by a sensor arranged to control the memory element to modulate the emitted light pulse signal to compensate for short-term variations occurring in the light signal transmission path.

Abstract: A photoelectric detector for detecting the presence of an object which comprises at least a light ray projecting element, for example, of a luminescent diode and a light ray receiving photoelectric element, for example, of a photo transistor. The two elements are respectively received in bores formed in a housing in such a manner that only the light rays emitted by the projecting elements is received by the receiving element with any lights due to irregular reflection prevented from reaching the receiving element so as to avoid erroneous functioning of the detector.

Abstract: A low distortion modulated light source, including a light emitting diode and a compensating diode. These diodes are arranged in parallel for D.C. biasing, and in anti-series with respect to the A.C. signal path. Means are provided for varying the relative biasing of the two devices so as to thereby adjust the A.C. characteristics of the compensating diode to more accurately correspond to the A.C. characteristics of the light emitting diode.When properly biased, the inherently non-linear junction capacitance of the light emitting diode is compensated so as to substantially eliminate undesired harmonics and intermodulation products.

Abstract: A light transmitter for use in a light activated T.V. remote control system. A modified cylindrical lens having a wide horizontal dispersion angle and a reduced vertical dispersion angle is directly coupled to a light emitting diode. The resulting combination provides a controlled light dispersion suitable for transmitting to a distant receiver location.

Abstract: A signal reproducing system using light for reproducing video or other information signals recorded on a recording medium, such as a rotatable disc, employs a semiconductor diode laser for directing the light to the recording medium which has reflective portions and nonreflective portions representing the recorded signals. A cleavage face of the semiconductor diode has an antireflecting coating through which the light is directed toward the recording medium so that the semiconductor diode laser emits laser light only when the semiconductor diode laser receives the reflection from the reflective portions of the recording medium, and a transducer receives the laser light emitted from another cleavage face of the semiconductor diode laser to reproduce the recorded signals in response to the emitted laser light.

Abstract: A smoke detector and alarm system incorporating means for detecting airborne particles of smoke and activating an alarm for fire warning purposes, the system including an illuminating circuit having a light emitting diode therein, a smoke sensing and compensation circuit having a pair of photo-electric cells incorporated therein, a comparator and a trigger circuit, and an alarm circuit.

Abstract: A photoelectric sensor includes a photodetector, a lens, and a light source all mounted within a framework for holding the lens with the photodetector and light source located on the central axis of the lens. The photodetector is positioned on the rear side of the lens within the framework at approximately the lens focal point. The light source is positioned to emit light away from the front side of the lens. Structure in the form of an opaque collar is provided for mounting the light source relative to the lens to prevent impingement of spurious light from the light source upon the lens. An object positioned in front of the lens intercepts the emitted light from the light source and reflects it back toward the lens, whereupon it is directed to the photodetector. A signal indicative of the presence of the object is provided by the photodetector responsive to the reflected light.

Abstract: A compact and portable colorimeter, including an integrally-formed probe having both a solid-state source of relatively monochromatic light and an optically coupled photodetector mounted therein. A power oscillator gating means is connected to the light source for pulsing same, to provide a chopped optical input. A demodulating circuit receives the output from the photodetector. The power oscillator gate signal is provided to a synchronous detector at the demodulating circuit, to synchronize detection with the chopping. The output from the demodulator is converted to a signal and read-out indicative of the concentration of that component of the sample which has absorbance characteristics correlated with the wavelength of the monochromatic source.

Abstract: An ornamental ring having a flashing capacity controlled by a minute electrical circuit incorporating one or more light-emitting diodes which are confined in the gem-display region of the ring, is disclosed. A time delay, capacitor-resistor arrangement governs the activation and deactivation of a pair of transistors whose function is to cause the light-emitting diodes to alternately flash or blink in substantially identical intervals.

Abstract: Smoke detection apparatus including a pair of photoelectric cells which receive illumination selectively from a very low level light source. One of the cells is termed the "direct" cell because it is in the direct path or on the axis of a narrow conical beam of light emanating from the source, the other cell being termed the "reflected" cell because it receives a significant part of its light input upon reflection of light from smoke particles or the like as such particles are drawn into the path of the light beam. Under predetermined smoke conditions, i.e., when there is smoke obscuration of the light of 2% per foot (.01 optical density), an alarm signal is triggered. The very low level light source is a light-emitting diode which sensitively monitors the smoke obscuration; only a slight change in the illumination to the pair of photocells, connected in a sensing circuit, is required to produce the triggering signal.

Abstract: An opto-electronic photocoupling device in which the light emitter and receiver are coupled optically by a light conductor, and the conductor is constituted by a drop of a first transparent resin embedded in a second resin which is also transparent, the index of refraction of the first resin being higher than that of the second resin.

Abstract: A method and portable apparatus for measuring particulate concentration in the atmosphere utilizing uniform laser pulses to traverse the atmosphere to be measured and a photo-electronic receiver which discriminates against stray light and detects the attenuation of the laser pulses. This attenuation is caused by particulates in the atmosphere which tend to scatter or absorb light. By using monochromatic laser pulses having wavelengths lying in transparent atmospheric windows, error is not introduced by the attenuation of the beam due to gases occurring naturally in the atmosphere including water vapor. Thus concentration of particulates such as smoke, fog, smog, dust and the like are measurable.

Abstract: Optical radiation generation and detection using metal-to-metal diode junctions. Coherent optical radiation is generated by using an antenna connected to a metal-to-metal diode junction with non-linear current-voltage characteristics and by coupling to the junction electromagnetic radiation energy to interact with the junction, causing emission from the antenna at optical frequency absent from the input. Optical diodes are shown in the forms of a mechanically contacted cat whisker system and as single and multiple microscopic solid portions in an integrated solid mass, defining both the antenna and the junction, preferably as a deposit of solid layers upon a substrate, preferably as overlapping printed circuit line structures. Arrays of such junctions provide enhanced effects; useful arrays include Franklin-Marconi geometries, fish-bone antennas and row and column arrays.

Abstract: A light emitting diode is driven by an input signal and electromagnetically coupled to a photodiode. The photodiode is connected to a high impedance load across which is obtained a signal linearly related to but electrically isolated from the input signal.

Abstract: An optical transmitter-receiver system is provided which is particularly adapted for use in vehicle guidance, obstacle detection and the like. The system includes a laser diode transmitter including a modulation circuit comprising a bank of transistors that are individually triggered into the alvalanche mode so that energy stored by a capacitive storage network is discharged into the diode. In accordance with a first receiver embodiment, which includes a range flip-flop controlled by a threshold comparator, an analog voltage proportional to range is produced. In a second receiver embodiment, the receiver responds to targets within a prescribed zone determined by an analog gated amplifier.

Abstract: This relates to a light emitting diode circuit wherein a coil is connected to a voltage source, the voltage of which is lower than the threshold voltage of the forward diode characteristic. The light emitting diode is connected in series via the coil to the voltage source, and a transistor operating as a switch is connected in parallel to said light emitting diode.

Abstract: An electro-optical ranging system is disclosed for purposes of measuring or determining the distance from a transmitting/receiving location to an object, such as a target. An electro-optical transducer, such as a laser diode, is employed which exhibits the characteristic of emitting radiant energy in the infrared region when driven into a conductive condition and also exhibits the characteristic of being in a photovoltaic condition in response to receipt of radiant energy within the wavelength of the energy emitted. The transducer is periodically driven so as to emit radiant energy, and an optical directing means, such as an optical lens system, is employed for purposes of directing emitted energy from the transducer along a path toward the target as well as for receiving energy traveling in the opposite direction from the target and directing the received energy so as to impinge upon the transducer such that the transducer is actuated to a photovoltaic condition.

Abstract: A fiber coupled light emitting diode module is provided which may be utilized for plug-in incorporation into a fiber optical communications system and for easy connection to a driving voltage source. Means are included in the module for facilitating manufacture since the location of the light emitting diode is not critical within the device and the device may be operated efficiently since the heat which is generated at the light emitting diode is conducted away to the exterior of the module for dissipation.