Abstract: A mechanism for achieving single frequency output in a semiconductor laser diode is disclosed. In accordance with the invention, a conventional laser diode having an anti-reflection coating on its output facet is coupled to a single mode fiber output pigtail having an anti-reflection coating on its input facet. The anti-reflection coatings suppress Fabry-Perot type feedback which would normally be effective for a large number of wavelengths. The fiber includes a built-in distributed Bragg reflector grating, which grating is located just beyond the output fiber input facet. The grating supplies feedback that is effective only over a narrow wavelength band approximating the wavelength spacing between the actual longitudinal modes of the structure so that the laser produces only a single frequency output.

Abstract: An optical fiber submarine cable having only a central rope for withstanding the stresses to which the cable is subjected, a plastic core with interrupted but closed or substantially closed, grooves at its outer portion, at least one optical fiber in each groove, a sheath around the core, and a substantially incompressible fluid filling all otherwise empty spaces within the sheath including any such spaces between the wires of the rope and in the grooves. The grooves are separated by ribs, and before the sheath is applied the diameter of the core at the ribs is greater than the diameter of the inner surface of the sheath and the sides of the ribs are separated to provide grooves opening outwardly of the core. Also, a process for manufacturing such a cable.

Abstract: A fiber optical connector for splicing optical fibers end-to-end in axial alignment. The connector housing comprises a bottom section and three top sections, each hingedly attached to the bottom section. The bottom section has chambers with the V-shaped grooves for inserting and properly orienting the optical fibers end-to-end. The top end sections each contain lands or fingers which, when closed, urge the fibers into the correct position within the V-shaped grooves and lock them there by exerting pressure on the protective jackets surrounding the fibers. The center top section has a land or finger which closes directly onto the end optical fibers, forcing correct and precise alignment and locking them in this orientation. A tension or strain relief may be installed over the connector. The connector permits final inspection of the fiber orientation and application of an index matching fluid prior to closing the center segment.

Abstract: A streaking tube has fiber cables, and the fiber cables are buried in a faceplate made of glass or fiber and arranged in line passing through the center of the faceplate so that the inner edges of the respective fiber cables are set to the inner surface of the faceplate. A photocathode is formed thereon. Any faceplate areas other than those of the fiber cables are shielded to eliminate unwanted noises.

Abstract: A coupler (FIG. 4) comprising a pair of interwined monomode fibers optically coupled along a portion of their length. The diameter of one fiber is significantly smaller than that of the other and this fiber is thus wound helically. A helical pitch not exceeding 10 mm is chosen. For such pitch, the smaller diameter fiber is appreciably longer. The following inequality thus holds:.lambda..sub.c .multidot.L/.DELTA.L.ltoreq.L.sub.c :where.lambda..sub.c is the design wavelength,.DELTA.L/L is the difference in fiber lengths per unit length, and L.sub.c is the interaction length of the coupler. The signal coupling of the coupler is than a strongly peaked function of wavelength. The coupler is suited to wavelength multiplex/demultiplex applications.

Abstract: An electro-optic switch implemented on a substrate which includes first and second input waveguides of unequal width and a central region in which light from the two input waveguides converge. First and second output waveguides are provided which diverge from the central region. Electrodes for generating an electric field are disposed adjacent the central region and output waveguides for switching a beam of light from the first to the second output waveguide in a step-like manner in response to a control voltage.

Abstract: There is provided an optical fiber communication cable as described including at least one rigid tension element provided in combination with conventional single tube loose buffer cable and grooved spacer core cable constructions in order to provide greater tensile strength and an enhanced operating temperature range.

Abstract: A dead end appliance for a fiber optic cable includes a housing having an elongated opening therethrough. The elongated opening is angularly disposed with respect to a longitudinal axis of the housing and opposite to the lay angle of helical retaining rods surrounding the cable. This conformation assures full capture of the retaining rods within the housing. Strengthening ribs for the housing are disposed substantially normal to the housing longitudinal axis. Additionally, means for grounding the assembly is integrally formed with the housing, and either a U-shaped member or a pair of clevis members may be used for attaching the housing to an associated support.

Abstract: A first (1) and a second (4) optical fibre are each retained in its holder (2, 5) by which the ends of the fibres may be centered at a contact location (6). Each of the fibres is bent at a radius (R.sub.1) dependent on the light wavelength in its respective light coupling means (8, 9) for coupling light to the fibres. Light from a light source (11) passes the contact location (6) and is measured with the aid of a light detector (14) and a measuring instrument (16). For each fibre (1, 4) the apparatus has a mode filter including a cylinder (17, 18) about which the fibre is bent half a turn. This cylinder has a radius (R.sub.2) which is greater than the cylinder radius (R.sub.1) in the light coupling means. A light signal (I.sub.1) has a basic mode (I.sub.2) with symmetric energy distribution, which passes through the first mode filter (17), while higher order unsymmetric modes (I'.sub.1) are filtered away. A light signal (I.sub.3) in the second fibre (4) has higher order modes (I'.sub.

Abstract: The eccentricity of the core of the light guide fiber relative to the outer casing of the light guide end portion is detected by viewing the end face while simultaneously rotating the light guide end portion. When an eccentricity is detected, the light guide fiber is displaced by impressing an impressing segment into the end face of the light guide end portion until the core of the light guide fiber extends coaxially with respect to the central axis of the light guide end portion. For that purpose the light guide end portion is clamped in an adjusting device under a microscope.

Abstract: An array of light guides having limited internally reflective wall surfaces allows projection of an array of tightly defined light spots with minimal cross talk between spots. The walls are fabricated from an optically absorptive material and the wall surfaces have an index of refraction which is greater than the index of refraction of the guide channel medium. The dimensions of the array are such that light from an emitter propagates through the channel associated with that emitter while light entering that channel from another emitter is absorbed within the channel walls.

Abstract: A plane or "board" for use in the interconnection of a plurality of optical circuit devices is disclosed. Each circuit device will have attached at least one optical signal transmission fiber or rod for the express purpose of communication external to such device by optical means, as well as any means for the purpose of electrical signal transmission. Electrical interconnections are provided using traditional methods, including the use of soldering techniques. Optical interconnections are afforded by means of optical rods or filaments which originate in the circuit devices themselves, and are joined to the optically conducting path of the circuit board by use of either sonic of ultrasonic acoustical energy. The use of acoustical energy in this manner will produce a welded junction which couples optical signals between these two materials. This ultrasonic welding procedure can be accomplished using a handheld tool, much as an electrical soldering iron is presently used.

Abstract: A fiber optic coupler is provided having first and second optical fibers fused together along a predetermined length having fused tapered ends for the input and output of optical energy and a constant diameter section therebetween to facilitate coupling of optical energy between the first and second optical fibers. The constant diameter section provides a higher efficient coupling action and a stronger, more rugged coupler.

Abstract: An optoelectronics package 1 comprising, an optical bench 12 along which is defined an optical axis 43, a semiconductor laser 21 along the optical axis 43, a lens 27 focused on the laser 21 and transmitting optical emission from the laser 21 along the optical axis 43, an optical fiber 45 having an optical face 48 aligned with the optical axis 43, and the fiber 45 is secured to the optical bench 12 with a column load applied on the fiber 45.

Abstract: The endoscope tip adaptor has an objective optical system capable of varying the observing direction with respect to the optical axis of an endoscope side optical system and a light guide of an optical axis inclined with the optical axis of an endoscope side light guide, is to be removably fitted to an endoscope tip surface, secures a space so that the light guide may not be broken and expands the range which can be observed.

Abstract: An improvement in a light waveguide plug which enables compensating for offsets due to tolerances in the parts characterized by a plug pin having an internal clamp seat for receiving a swivel member. The swivel member has a projection or stem with a portion extending out of a free end of the plug pin. The end sticking out of the plug pin has the waveguide surface flush with the surface of the end and that surface has a crown or slightly convex surface. The swivel member can be moved so that the offset can be corrected up to approximately 4.mu.. Thus, the end of the optical fibers exit and entrance surface can be concentrically disposed to lie on the axis of the waveguide plug.

Abstract: Waveguide apparatus for use in substance analysis has a waveguide, with a surface area in contact with the substance, for transmitting electromagnetic radiation along the axis of the waveguide whereby propagation characteristics of the radiation are altered in accordance with properties of the substance adjacent the waveguide. A waveguide entrance prism is positioned at the radiation entrance end of the waveguide, for guiding radiation into the waveguide. The prism has a first face arranged at an angle with the waveguide axis to cause radiation entering the prism to propagate along the waveguide. In one embodiment, a longitudinal partition is arranged adjacent the waveguide substantially parallel to the waveguide axis, for partitioning the waveguide surface area into at least two parts so that multi-substance analysis can be carried out.

Abstract: A unitary optical-fiber connector assembly accepts a plurality of input channels and, by means of a common transfer lens of the graded-index type, transfers the input-channel data to a corresponding plurality of optical-fiber output channels.