Abstract: A mechanical regulation system for controlling tow line payout between the aerobody and a towing vehicle. The system comprises a housing, a nonrotating spool, and a tow line wound around the spool that is coupled between the aerobody and the vehicle. The regulation portion of the present system comprises a rotatable wedge-shaped tube, having the tow line wrapped around it. A rotatable mechanical regulator is slidably coupled to the wedge-shaped tube. The regulator is adapted to rotate with the tube and move transversely along the length of the tube as the tow line is removed from the spool. A brake mechanism is provided as part of the regulator, and a brake drum is disposed adjacent the periphery of the regulator that is contacted by the brake mechanism.

Abstract: A launching and regulation system that incorporates an expendable towing and deployment mechanism for use with a towed aerobody that provides for launching and controlled tow line payout between the towed aerobody and a towing vehicle. The system comprises a housing, a nonrotating spool disposed in the housing, and a tow line wound around the spool that is coupled between the aerobody and the vehicle. The tow line preferably comprises a photonic, fiber optic, link. The launching mechanism comprises a plurality of impulse cartridges for deploying the aerobody and severing the tow line at a predetermined time. A spring piston is disposed inside a wedge-shaped tube that confines expanding gasses within the tube that are generated by an impulse cartridge and moves the spring piston to launch the aerobody. The regulation mechanism may comprise a mechanical system or adhesive resin system. The mechanical system comprises a rotatable wedge-shaped tube, and the tow line is wrapped around it.

Abstract: An optical fiber dispenser (40) includes a bobbin (42), an optical fiber pack (52) overlying the bobbin (42), and a thermal expansion accommodation layer (50) positioned between the bobbin (42) and the optical fiber pack (52 ). The thermal expansion accommodation layer (50) is made of a material, such as a silicone elastomer, that is readily deformable to accommodate the different longitudinal coefficients of thermal expansion of the bobbin (42) and the optical fiber pack (52). The thermal expansion accommodation layer (50) has a thickness, typically more than about 1/8 inch for a conventional bobbin size, sufficient to reduce any thermal stresses produced by the different longitudinal coefficients of thermal expansion to less than the failure strength of the optical fiber pack (52).

Abstract: A bi-directional erbium doped fiber (EDF) optical fiber amplifier (50) employing two separate EDF amplifier channels (52, 62) for two counter-propagating signals allows the optimization of each individual signal channel for efficient bi-directional optical signal repeater performance. The pump sources (53, 63) for each EDF channel (52, 62) can be switched on and off independently, to serve as an in-line signal switch, without affecting another signal channel.

Abstract: A tethered vehicle such as a missile system comprises a tethered vehicle body having a control system and propulsion system therein, a control station for the tethered vehicle located outside of the tethered vehicle body, and an optical fiber data link extending from the tethered vehicle control system to the control station. The tethered vehicle system further includes a GPS positioning system for the tethered vehicle, which comprises a positioning signal receiving antenna mounted in the tethered vehicle, and a positioning signal amplifier mounted in the tethered vehicle, which receives a positioning signal from the antenna and produces an amplified positioning signal. A transmitter transmits the amplified positioning signal into the optical fiber data link at its end within the tethered vehicle, and a receiver receives the amplified positioning signal from the optical fiber data link at its end at the control station. A signal processor analyzes the amplifier positioning signal received from the receiver.

Abstract: A bidirectional optical fiber (12) amplifier suitable for use in a dual payout fiber-optic communication link (10) is disclosed herein. The inventive amplifier (12) is typically encasted in a shell or service loop, and is preferably connected between first and second optical fiber segments (18 and 20). The amplifier (12) includes a pump laser (102) for generating optical energy of a first wavelength. A wavelength selective optical coupler (82), in optical communication with the first fiber segment (18) and the pump laser (102), combines optical energy propagating through the first fiber segment (18) with the optical output of the pump laser (102). The amplifier (12) of the present invention further includes a doped optical fiber (114), optically connected between the wavelength selective optical coupler (82) and the second optical fiber segment (20), for amplifying optical energy within a predetermined wavelength spectrum passing therethrough.

Abstract: A figure eight linear dispenser (10) having an optical fiber winding configuration adapted to dispense an optical fiber waveguide (14) at high speed. The dispenser (10) is built up of a series of flat winding layers, with each layer comprising an interlaced figure eight pattern. More particularly, the dispenser (10) comprises a housing having a pair of bobbins (12a, 12b) respectively centered on a pair of half-circular outer guides (13a, 13b). The optical fiber waveguide (14) is wound around the bobbins (12a, 12b) inside the outer guides (13a, 13b) in a series of layers (15a-15e) of figure eight loops (16a-16e). An optional cover may be disposed over the bobbins (12a, 12b) and the guides (13a, 13b) in order to enclose the waveguide (14). The waveguide pay-out of the dispenser (10) through a properly spaced eyelet (17) is nearly helix-free and linear as a result of cancellation of the angular momentum in the paired figure eight loops (16a-16e).

Abstract: The bobbin of an optical fiber canister is constructed so that the thermal expansion coefficient of the bobbin is matched to that of the optical fiber pack wound upon the bobbin. In one embodiment, an optical fiber canister (20) has a bobbin (22) in the shape of a frustoconical shell (24) with a flange (26) at one end of the shell (24), the bobbin (22) having a slot (34) through the shell (24) and the flange (26) extending longitudinally parallel to the axis (28) of the shell (24). In another embodiment, an optical fiber canister (50) has a bobbin (52) in the shape of a frustoconical shell (54) with a flange (56) at one end of the shell (54), the bobbin (52) being formed of at least two layers (62) of structural fiber (60) material helically wound and adhesively bonded into the shape of the shell (54). The structural fiber (60) material is selected to have substantially the same thermal expansion properties as optical fiber material, and may in fact be optical fiber.

Abstract: An optical fiber canister (90) comprises a hollow housing (102) and an optical fiber pack (98) having a plurality of layers of optical fiber (20) supported on an inner surface of the housing (102) with a free end (96) of the optical fiber (20) positioned to pay out from an interior surface of the fiber pack (98). The optical fiber (20) of the optical fiber pack (98) has an amount of adhesive thereon ranging from zero to an amount sufficient to produce a peel force of less than about 2 grams. There is desirably a support layer (110) of a castable elastomeric material between the inner wall (108) of the hollow housing (102) and the outer surface of the optical fiber pack (98), and a release layer of a release material such as polytetrafluoroethylene between the inner surface of the support layer (110) and the outer surface of the optical fiber pack (98).

Abstract: A missile data link filament (12) dispenser (10) is located within an enclosure (20) having a single eyelet opening (26) through which the filament feeds on launch. A quantity of a damping gas having an effective density of at least about two times that of air (28) is provided within the enclosure (20). The gas serves to damp the helical motion of the filament by absorbing its rotational energy, to inhibit ballooning of the filament (12) as it is paid out from the dispenser (10).

Abstract: A missile data link filament (12) dispenser (10) is located within an enclosure (20) having a single eyelet opening (26) through which the filament feeds on launch. A quantity of a particulate material (28) located within the enclosure (20) is converted to an aerosol mixture by the filament movement on dispense. The aerosol mixture serves to act as a brake on the filament preventing dispense speed exceeding a predetermined desirable maximum.

Abstract: A dispersion equalization technique for correcting dispersion-induced signal degradation within optical fibers is disclosed herein. The present invention prescribes a technique for synthesizing an optical fiber R of length L adapted to induce substantially zero dispersion at a wavelength W' included between first and second wavelengths W1 and W2. The optical fiber R includes first and second segments M and C of variable lengths L.sub.1 and L.sub.2 which induce substantially zero dispersion at the wavelengths W1 and W2, respectively.

Abstract: The optical characteristics of an optical fiber (28) are studied by simultaneously introducing multiple small-radius bends into a short length of the optical fiber (28). Since there is a small loss of light associated with each bend, those losses are added and made easier to measure and analyze when multiple bends are used. The optical fiber (28) is wound over a mandrel (10, 50) that is shaped to include at least two simulated peel location bends of the optical fiber (28) wound onto the mandrel (10, 50), and, preferably, four or more simulated peel location bends per turn of optical fiber (28) around the mandrel (10, 50).

Abstract: An optical fiber is proof tested by bending it relative to the fiber axis by a preselected amount, in all directions and at all locations along the length of the fiber. In one approach, the optical fiber is wrapped around a cylindrical mandrel in a helical pattern and drawn over the mandrel through its entire length. With the preferred helical angle of about 45 degrees, two wraps of the optical fiber around the mandrel ensure that all of the fiber will be bent in all directions. If a flaw exists in the optical fiber that would cause failure at any amount of bending below that of the preselected amount, this proof test will cause the fiber to fail so that the weak point may be eliminated.

Abstract: An optical fiber is joined, preferably with an ultraviolet curable adhesive, to a strip of a flexible support material such as a plastic tape to form an optical fiber assembly. The assembly is wound onto a bobbin to form an optical fiber canister, which is then paid out upon demand. The optical fiber assembly requires little or no adhesive to hold it in place on the bobbin, as the support material of each turn aids in holding the adjacent turns in place, with the result that the bend radius during payout is increased.

Abstract: A process for preparing a glass rod having a graded refractive index for use as the start rod in the production of optical waveguides is disclosed. The process comprises depositing and sintering borosilicate particles on a glass rod to form a rod having a larger diameter than the original fused silica rod and drawing this rod to obtain a start rod having the same diameter as the original glass rod but exhibiting a partially radially graded refractive index. Optical waveguides prepared from such graded start rods have a more uniformly graded radial index of refraction profile.

Abstract: A process for preparing a preform for the production of optical fiber by depositing and sintering glass particles upon a glass rod is disclosed. The process comprises directing a stream of glass particles onto the surface of a glass rod which is slowly rotated and moved in a translational direction so as to obtain even deposition of the particulate matter. A separate heat source is supplied beyond the point of deposition of the particles and continuously sinters the deposited particulate as the rod undergoes repeated translation.

Abstract: A process for preparing a glass rod having a graded refractive index for use as the start rod in the production of optical waveguides is disclosed. The process comprises depositing and sintering borosilicate particles on a glass rod to form a rod having a larger diameter than the original fused silica rod and drawing this rod to obtain a start rod having the same diameter as the original glass rod but exhibiting a partially radially graded refractive index. Optical waveguides prepared from such graded start rods have a more uniformly graded radial index of refraction profile.

Abstract: Apparatus and process for automatic control of the production of optical fiber are disclosed. The process comprises continuously depositing and sintering borosilicate glass particles on a fused silica rod or a graded index rod in such a manner that the glass exhibits a uniform, radially increasing concentration of boron. The appropriate boron oxide/silica concentration ratio in the glass particles is controlled by the time of deposit and the weight and diameter of the rod, which are continuously monitored. The concentration of boron oxide and silica in the particulate is likewise continuously monitored to insure that the correct portion of boron oxide/silica is deposited.The apparatus for conducting the process, includes means for continuously monitoring the weight and diameter of the rod and the boron oxide content of the glass particles and means for automatically regulating the equipment used to produce the optical fiber in response to readings from the monitoring means.

Abstract: A process for continuously monitoring the content of boron oxide in a stream of borosilicate particles as it is applied to a glass rod during the production of optical fiber is disclosed. Monitoring is accomplished by continuously measuring the infra-red absorption bands of the particles at or near the point of deposition on the rod.