Abstract: A fiber optic coupler of the type wherein first and second single-mode optical fibers, each having a core and a cladding, are fused together along a portion of the lengths thereof to form a coupling region. The fiber diameters are smaller in the coupling region than in the remainder of the fibers. The cladding of the second fiber contains an amount of chlorine sufficient to increase the refractive index n.sub.2 ' thereof to a value greater than the refractive index n.sub.2 of the cladding of the first fiber.

Abstract: An activation mechanism for an optical switch is disclosed. The mechanism is particularly suited for use with switches requiring the movement of a reflecting element into and out of an optical signal path to provide switching. The mechanism consists of a reflecting element (e.g., mirror) and a means (e.g., magnetic, electrostatic, vacuum) for moving the reflecting element into and out of the optical signal path. In the absence of any applied signal, the reflecting element is positioned to intercept an optical signal and redirect it into the chosen output signal path. Upon the application of an external signal, the moving means will create a force of a strength sufficient to move the mirror and allow the optical signal to pass through the switch unobstructed by the reflecting element.

Abstract: In a Mach-Zehnder electro-optic modulator (10), an optical waveguide (14) includes two branches (20,22) extending between an optical input (16) and an optical output (18) is formed in a substrate (12) of a material having electro-optical properties. An electrical signal applied to a modulation input (34) affects the material such that the effective optical lengths of the branches (20,22) vary differently in correspondence with the magnitude of the electrical signal. The optical signals propagating through the branches (20,22) interfere with each other at the optical output (18) at a phase angle depending on the difference between the effective optical lengths. A selected electrical bias voltage applied to the modulation input (34) causes non-linear modulation of an input optical signal with one or more even integral multiples of an electrical input signal which is additionally applied to the modulation input (34), thereby providing frequency multiplication.

Abstract: A composite tape structure having a metal tape layer and a layer of swellable water blocking material, the two layers bonded together face-to-face. The tape structure is for use as a composite shield and water blocking structure surrounding the core of a cable, preferably a telecommunications cable. One edge region of the metal tape layer may extend beyond the layer of water blocking material so that overlapping edges of the metal tape layer confront each other for bonding purposes when used as shield. The layer of water blocking material may be formed from tape impregnated with or provided with a paticulate swellable material, or the particulate material may be applied directly to and bonded to the metal tape layer.

Abstract: A pulling eye assembly for optical fiber cables is formed of a housing having a gripping device for gripping the multiple strength members. The first embodiment uses longitudinally extending cavities which communicate with radially directed threaded set-screw holes for receiving epoxy and/or set-screws. In the second embodiment, a pair of collets are used to grip the strength members. In both cases, a crimping sleeve is attached to an end of the cylindrical housing and being crimpably engageable with an outer surface of an optical fiber cable.

Abstract: A novel optical fiber structure is described which includes an end thereof for transmitting optical signals and substantially reducing reflections of optical signals thereat wherein the fiber end has a substantially flat end surface disposed at an angle to a plane perpendicular to the transmission axis of the fiber equal to or greater than sin.sup.-1 (NA/n) where NA is the numerical aperture and n is the index of refraction of the fiber core material, and the fiber outer surface has adjacent the end surface a flattened portion of preselected depth and length whereby substantially all paraxial and meridional optical signals propagated along the fiber axis are transmitted through the end surface and skew rays transmitted along the fiber are substantially attenuated near the fiber end.

Abstract: An attachment and disengagement tool (30) is provided for a bayonet connector (1) for an optical fiber cable (2). The bayonet connector (1) comprises a coupling nut (14) moveable axially over the body of the connector (1). The nut (14) has a pattern of raised knurls (21) and further has J-shaped bayonet slots (22) for accepting of the bayonet pin (23) of a coupling bushing (24) complementary to the connector (1). The attachment and disengagement tool (30) comprises a trough-shaped main body (31) with cup-shaped center bore (32) extending therethrough, and a cradle-shaped forward extension (36) with cup-shaped bore (37) coextending with the bore (32) of the main body (31) and partially inset into the front of the main body (31) to form a partial annular shoulder (38) at the intersection of the extension (36) with the main body (31). The extension (36) has forward-extending L-shaped engaging tangs (39) with rear stems (40) forming latching recesses (41) circumferential to the common bore (32, 37).

Abstract: A reinforced optical fiber including a single optically guiding fiber, a nonmetallic intermediate layer of flexible strength members conforming to the fiber and tapering at a pre-determined rate to expose the fiber, and a metal sheath around the fiber and intermediate layer conforming to the intermediate layer and terminating prior to the taper of the intermediatae layer. A method of manufacturing the fiber sheathed in a metal casing including the steps of separately feeding the optical fiber surrounded by the intermediate layer and the casing material into a die, and drawing the encased fiber from the die. The method also includes measuring and adjusting the tensions of the fiber, casing material, and encased fiber. A die for sheathing the optical fiber includes a die block, an entrance for the fiber and casing material, a continuous and smooth shaping chamber, and an exit for the encased fiber.

Abstract: An optical switch system including an optical switch apparatus which includes a light source emitting light of a certain wavelength, a single optical fiber cable for transmitting the light to a terminal switch, radiating means for radiating the light transmitted over the optical fiber cable, a reflector that is provided in the optical path of the radiated light at such a position that the reflected light will reach the radiating means, a shutter adapted to be inserted into or removed from the optical path of the radiated light, and a light extractor for detecting the reflected light wave that has passed through a return path in the optical fiber cable.

Abstract: The invention relates to optical systems comprising thin film optical waveguide isolators that are characterized by linear birefringence at least some wavelengths and temperatures. Disclosed is a method for using such a system at more than one wavelength and temperature.

Abstract: An optical transmission element that has an oil-containing filling compound and inside is provided with a two-layer outside sheath. The inside layer of the sheath is composed of a polyolefin and the outside layer is composed of a polyester, particularly of a polycarbonate. The shrinkage and swelling of the inside layer is largely compensated by the hard outside layer and the swelling portion, which usually appear at higher temperature, are kept extremely low.

Abstract: An optical source for use in an optical sensing system such as a wavelength division multiplexing system. The source produces an optical interrogation signal comprising a plurality of component signals, each component signal comprising light in a wavelength band different from the wavelength bands of the other component signals. The source comprises a concave diffraction grating, means for forming an aperture at which the interrogation signal will be formed, and a plurality of optical emitters. Each emitter is positioned such that the emitter output signal strikes the concave diffraction grating, and is focused onto the aperture, such that a portion of the emitter signal enters the aperture and forms one of the component signals. As a result, the component signal wavelengths are not sensitive to temperature-induced fluctuations in the emitter output signal.

Abstract: The photorefractive effect results in a change in the refractive index of bulk chalcogenide glass when it is exposed to certain wavelengths of light, in particular, sub-band-gap light. The effect results in a variety of device structures including a fiber optic faceplate; an optical waveguide; a fiber tap; a lens and a Bragg grating. Methods for fabricating the various devices are described.

Abstract: A refractive index FOCS has a fiber optic core with a partly light transmissive thin metal film clad of an effective thickness and light transmissivity so that transmission through the core is strongly affected by the refractive index of a surrounding liquid or vapor medium. The metal clad and surrounding medium produce a localized refractive index at the core interface which modulates light transmission through the core as a function of the medium refractive index. The clad is made of platinum, or also of gold, rhodium, palladium, nickel, iron, cobalt, ruthenium, iridium, osmium, zinc, copper, silver, chronium, molybdenum, tungsten, vanadium, niobium, tantalum, titanium, zirconium or hafnium. The clad is also made of oxides of these metals, or metal compounds or alloys. With a fluorescent tip, the changes in the fluorescent signal are a measure of the medium refractive index. With a reflective tip, the changes in the reflected signal are measured.

Abstract: An apparatus for coupling two optical elements comprises a plurality of optical fibers, a plurality of first substrates stacked in a first direction, and a plurality of second substrates stacked in a second direction perpendicular to the first direction. Each optical fiber is fixed to one of the first substrates and a corresponding one of the second substrates such that none of the optical fibers cross over one another.

Abstract: A connector employs a glass sleeve having a ceramic ferrule fixed in one end and containing an optical fiber having its presentation end factory ground. The opposite end of the glass sleeve is formed to receive a fiber during a field installation. The middle portion of the sleeve contains an elastomeric pair which receives the ends of the fibers.

Abstract: An optical fiber is constructed by selecting a first material for a core of the optical fiber. The first material has a known coefficient of thermal expansion, .alpha..sub.1, and a known temperature dependent rate of change, dn/dT, of an index of refraction, n. A second material (cladding) has a predetermined coefficient of thermal expansion, .alpha..sub.2, and a radius, R.sub.2, about the axis of the fiber. The radius, R.sub.2, of the cladding is determined such that an effective coefficient of thermal expansion for the fiber is substantially equal to the negative of the product of the reciprocal of the index of refraction of the first material and the temperature dependent rate of change of the index of refraction of the first material, i.e. .alpha.=(-1/n)dn/dT.

Abstract: A cable closure (20) which is suitable for aerial, pedestal, wall-mounted or buried use and which is suitable for enclosing connections between metallic or optical fiber transmission media includes a base (30) and a cover (32). The base and/or the cover include a plurality of openings through which extend cables. Connections (50) between transmission media of the cables are disposed between portions (51,52) of a superabsorbent compliant foam material. The portions of the foam material and the base and the cover are sized so that when the cover is assembled to the base, the foam material is compressed. Upon contact with water which may enter the closure, the superabsorbent foam material swells, molding about the connections to protect them from the water and expanding outwardly to seal any unintended openings in the housing and prevent the ingress of additional water.

Abstract: Transmission of one or more electrical signals from a rotatable to a stationary member is provided along one or more channels, with an array of optical emitters positioned in a circle concentric with the axis of rotation of the rotatable member. A concentric array of facing optical detectors on the stationary member is coaxially spaced from the emitters. As the rotatable member is rotated, the optical detectors are sequentially switched in sync with the corresponding rotation of the respective emitter which is transmitting the signal. The direction of transmission may be reversed by reversing the location of the emitters and detectors to the stationary and rotatable members, respectively. In an alternate configuration, a concentric cylindrical embodiment with a cylindrical surface having emitters or detectors thereon rotates within a concentric stationary cylindrical surface having a circular configuration of facing detectors or emitters, respectively, thereon.

Abstract: An automated computer controlled process optical fiber splicing system 11 which yields consistent, high strength, low loss, high quality splices. The system of the invention includes a positioning system 17, 21, 29, and 31 for moving at least two optical fiber ends 15 and 19 into relative alignment at a junction 23. A high intensity beam of energy 37 is directed at the junction 23 of the fibers to achieve the high temperatures required for fusing the ends thereof. The focus of the beam 37 is adjusted to control the temperature profile of the energy applied to the junction 23.