Abstract: A communications cable system comprises a plurality of cables joined end-to-end, each cable comprising a plurality of single-material optical fibers, and a plurality of joint accessories each joining the ends of an adjacent pair of cables. At the end of each cable is provided a plurality of short cladded-core optical fibers optically joined to the ends of respective single-material fibers. The other ends of the cladded-core fibers project and the projecting cladded-core fibers of the two joined cables are inserted into opposite ends of capillary tubes which are supported within the joint accessory. The cladded-core fibers of the joined cables abut end-to-end and are long enough to follow curved paths between the ends of the cables and the joint accessory through-bores, so as to be under axial compressive forces.

Abstract: A laser power meter is described which enables the direct measurement of the output power of lasers over a full range of differing beam wavelengths. The laser power meter includes not only the photocell for intercepting a laser beam and the needle-scale meter conventionally provided, but also calibration means for simple adjustment of the meter to provide a correct power reading irrespective of the wavelength of the beam whose power is being measured. The calibration means includes first and second pluralities of resistors which are selectively connected in series between the photocell and the needle-scale meter by switches which are calibrated in nanometers. A user of the device is able to obtain a true reading of the power in a laser beam merely by "dialing in" the wavelength of the beam and selecting the proper power range for the needle-scale meter.

Abstract: A system for compensating for magnetic disturbances caused by the rotating stirrer magnet of a photometer sample cuvette on the photomultiplier tube of the photometer. To obtain the required compensation, a companion similar magnet is located coplanar with and adjacent to the main stirrer magnet and is counter-rotated synchronously with the main magnet in opposite magnetic phase therewith. The two counter-rotating magnets are physically located symmetrically with respect to the photomultiplier tube so that their magnetic effects on the electron flow of the photomultiplier tube cancel each other out. The companion magnet may be the stirrer magnet associated with a reference cuvette mounted in side-by-side relation to the sample cuvette. The counter-rotating magnets may be gearingly coupled together and may be mounted coaxially with respective ejection plungers associated with the cuvettes.

Abstract: An integrated optical modulator for modulating optical signals in dielectric wave guides with the modulator having a substrate with two wave guides on a surface thereof extending in parallel spaced relationship with each other and including three parallel extending electrodes arranged on the surface of the substrate to apply a voltage to the two wave guides characterized by the modulator including two additional short couplers in the form of short coupling wave guides with the short couplers being spaced from one another on the wave guides and extending at right angles thereto, the couplers being separated from the said two wave guides by a dielectric low loss film.

Abstract: An optical waveguide system for transforming the output of a phase modulator into an amplitude modulation. Laser light propagating in the waveguide is forwarded into branches in the waveguide. An electrooptic material placed in one or more branches is electrically controlled to vary the phase in each branch causing different propagation modes. The branched optical radiation or coherent light is then recombined in a single branch and subsequently branched again with each subsequent branch propagating a different mode. By tapering one of the latter branches to zero thickness, selective modes can be blocked resulting in amplitude modulation.

Abstract: Energy propagating in a dielectric optical waveguide may be transferred from one mode of propagation to another by inducing a spatially undulatory variation in refractive index in the core of the dielectric optical waveguide. Such a variation may be induced by an electro-static field. The electro-static field may be directed either longitudinally of, or transversely of the dielectric optical waveguide. A suitably periodic electro-static field may be generated by positioning a suitable electrode structure about the dielectric optical waveguide. For certain applications it may be desirable to arrange for the spatial period of the electro-static field to vary in a random manner. By arranging for propagating modes to couple to non-propagating modes an optical modulator may be produced.

Abstract: A fiber optic transmission line suitable for use in a submarine cable wherein one or more helically formed optical fibers are positioned lengthwise within a flexible tubular member containing a semi-fluid gelantinous substance. Due to the helical form of the fibers, the fibers are not stressed even when the line is subjected to axial load. The gelantinous substance retains the fibers in their helical form and prevents abrasion of the fibers. A method for forming such a fiber optic transmission line is also disclosed.

Abstract: A multichannel record disc recording system comprises automatic gain control circuits for each of the multichannels a control voltage, representing the phases and levels of the multichannel signals, control the gain of the automatic gain control circuits. An operational circuit at the output of the automatic gain control circuits produces an output sum signal and a difference signal. The difference signal, is angle modulated and multiplexed with the sum signal. The resulting multiplexed signal is recorded on a record disc. Each of the automatic gain control circuits carries out a gain control operation so that the maximum level of the output sum signal does not exceed a predetermined level, and the maximum level of the output signal of the automatic gain control circuit exceeds one half of the predetermined level.

Abstract: An aperture in a hull is sealed by a fiber optic plug system that comprises a coherent array of optical fibers that are fused to form the mechanical and structural equivalent of a thick glass plate. Identical terminal blocks are located on either side of the plug. The blocks comprise a plurality of fiber optic channels supported by a matrix. At the end of each block closest to the plug, channels are arrayed in a tightly packed pattern to reduce the size of the aperture in the hull. The other end of the blocks are expanded to allow each channel to be easily accessed via discrete fiber optic cables.

Abstract: The comprehensive large scale integration of thin-film optical circuits is made possible by a series of related developments. The key concept is the isolation of the high index substrate, necessary to active devices, wherever it is desired to have a passive device, by the interposition of an oxide layer such as SiO.sub.2. It is preferred that the passive devices and the SiO.sub.2 by amorphous. This new arrangement allows the use of discrete thin-film corner reflectors, instead of distributed feedback, in resonant active devices and wherever a reflector or beam-splitter is needed. Further, the active devices may be located photolithographically by etching windows in the SiO.sub.2 layer. All of the active devices share a common active layer, which forms the passive devices wherever it extends between windows and simultaneously is the light guiding layer throughout.

Abstract: An elongated hollow termination pin assembly for mechanically terminating a fiber bundle of a fiber optic cable. The pin assembly includes an elongated hollow pin with coaxially slidable outer sleeve and an O-ring of resilient material mounted in a groove about the pin immediately adjacent to the end of the sleeve toward the terminal end of the cable. A backward facing shoulder is provided about the circumference of the sleeve so that a retaining clip within the connector shell can restrain backward axial movement of the sleeve. The pin can slide within the sleeve, however, and is resiliently constrained by the O-ring to provide a positive abutment force at the interface of the fiber bundles, dampen contact vibrations, and absorb axial tolerances. Alternatively, the O-ring may be positioned between a forwardly facing shoulder on the connector body and the retaining clip, with a tine on the clip engaging a rearwardly facing shoulder on the pin.

Abstract: A sound track selector system for a phonograph record player is provided comprising a light emitter and light detecting sensor carried beneath a sound stylus pick-up arm, directing light to the face of a phonograph record and receiving reflected light along axes substantially perpendicular to the record face and substantially parallel to one another as the emitter and sensor scan the record, means connected to the sensor for determining the bands between recorded sound in response to reflected light, and means for controlling the position of the pickup arm in response to preselected portions of the recording in relation to the detection of the unrecorded portions of the record. An optical encoder system is also provided for detecting the peripheral positions of the pickup arm with respect to the phonograph record.

Abstract: A muting circuit is provided for a phonograph record amplifier employing a semi-conductor cartridge wherein the cartridge has a shorting switch operative during the changing cycle wherein the amplifier associated with the cartridge is deactivated during the changing cycle of the pickup preventing transients in the output of the amplifier.

Abstract: There is provided a four-channel stereophonic reproducing system wherein each muting circuit comprises a limiter for limiting the carrier level of a frequency-modulated signal to a predetermined level, a control circuit actuated by the output of the limiter and a switching circuit controlled by the control circuit, whereby when the carrier level of the frequency-modulated signal decreases, the detected output of the sub-channel signal including a large amount of noise components is blocked by the muting circuit.

Abstract: A multichannel record disc reproducing system and apparatus comprises a phase-locked loop for demodulating an angle-modulated wave signal in a multiplexed signal picked up from a multichannel record disc. A synchronous detector compares the phases of the angle-modulated wave signal and an output signal of a voltage-controlled oscillator in the phase-locked loop. The detector produces an output signal when there is a noise component in the angle-modulated wave signal. A circuit, controlled by the output of the synchronous detector, provides a demodulated output signal having at least one attenuated frequency band, in which a noise component is greatly reduced.

Abstract: Telephone answering and message recording apparatus is disclosed which includes an outgoing message delivery system for delivering several messages to each caller, the messages to each caller being separated in time by intervening incoming message recording intervals, and the length of the intervening message recording intervals being determined by voice-operated circuits which determine, for each such interval, whether (a) the caller has started speaking, and whether (b) after commencing to speak, the caller has paused for more than a predetermined interval. After (a) and (b) have occurred, a circuit responsive to the voice-operated circuits initiates circuit action to commence the transmission of the next outgoing message to the caller. The disclosed apparatus includes circuitry for restoring the apparatus to its "awaiting call" condition if the caller remains silent for a predetermined interval after any outgoing message. Preferably, no non-speech signals (e.g.

Abstract: A video disc has a storage track formed of half wavelength pits alternating with lands. The track has a series of turns, individually of a generally circular path but undulating symmetrically about that path. The undulations of the several turns have such relative phase that the turns are in nested concentric relation and one component of the stored information represents the phase of the undulations.The record is a replication of a master formed under the control of a laser writing beam modulated with the information to be stored. A Bragg cell in the optical path, responding to a cyclic frequency-modulated signal, optically displaces the writing beam about a reference path to develop undulations in the record storage track.

Abstract: A video disc for an optical image reproducing system has a storage track formed of pits alternating with lands along a spiral path. The pit depth introduces a phase change of approximately .pi./2 radians between portions of a reading beam that impinge upon pits and portions that impinge upon lands adjacent the pits.

Abstract: In a four-channel stereophonic reproducing system of the type in which a first, second, third and fourth audio signals are reproduced from two stereophonic composite signals which are respectively comprised of a left side signal consisting of a main channel signal composed of the sum of the first and second audio signals and a sub-channel signal obtained by frequency modulating or phase modulating the difference between the first and second audio signals, and a right side signal consisting of a main channel signal composed of the sum of the third and fourth audio signals and a sub-channel signal obtained by frequency modulating or phase modulating the difference between the third and fourth audio signals, a detector circuit for detecting each sub-channel signal is followed by a filter circuit for eliminating undesired higher frequencies whereby to eliminate higher audio frequencies including increased noise components to improve the S/N ratio, and at the same time a phase correction circuit is provided in the