Abstract: A hydrophone includes a plurality of hydrophone components separated by finite spacings and interconnected to provide a single output signal. Each hydrophone component is based upon a single-mandrel design in which a cylindrical body is apportioned into sensing and reference sections. The sensing sections comprise coaxial arrangements of pliant inner and outer cylinders separated by an annular airspace while the adjacent reference sections comprise solid-walled cylinders. Finite separation distances between the hydrophone components result in reduced flow noise occasioned by increased sensing area while detection sensitivity is maintained.

Abstract: Optical fiber coils are formed on inner and outer mandrels. The inner mandrel is spaced apart from the outer mandrel to form a cavity between them with the inner fiber coil being inside the cavity. Water-tight seals between the inner and outer mandrels keep the inner coil isolated from underwater acoustic waves that may be incident upon the outer coil. The optical fibers are included in a dual optical path fiber optic interferometer that includes the inner fiber coil in a first optical path and the outer fiber coil in a second optical path. A central wall divides the inner region of the inner mandrel into two cavities. A tie rod has a first end connected to the wall and a second end extending out of the first cavity in the inner mandrel. A backshell is connected to the second end of the tie rod. The backshell includes a hollow portion formed as a housing for protecting fiber optic components of the interferometer.

Abstract: The inner surface affixation system and process is a method for affixing wound optical fibers on the inner surface of a hollow cylinder. It is useful, for example, in the manufacture of rigid mandrel-based fiber optic sensors. The optical fibers of a sensor wound on the inner surface are less susceptible to damage than are optical fibers wound on the outside of the mandrel.The process requires that the fibers be supported on a cylinder, which is coated with an adhesive and placed within the sensor mandrel cylinder, at which time the circumference of the supporting cylinder is expanded, causing the fibers to engage the inner surface of the sensor mandrel cylinder. The adhesive is then cured, holding the fibers in place on the inner surface of the sensor mandrel cylinder while the supporting cylinder is contracted and removed from the sensor mandrel cylinder.

Abstract: An omnidirectional fiber optic hydrophone includes a concentrically-arranged pair of ring-shaped mandrels mounted between planar upper and base members. Each of the rings is formed of inner and outer annular portions separated by an annular void. Optical fibers wound about the outer circumference of the outer annular portion of the outer ring and about the outer circumference of the inner annular portion of the inner ring communicate with a source of optical energy and with a photodetector to provide signals for measuring acoustic wave-induced deflections of the rings. A plurality of mandrels may be employed in a single hydrophone which may be potted with elastomeric material or free flooded.

Abstract: A housing for a fiber optic splice protects the splice from the external to environment. Two optical fibers may be butt-coupled in a connector, which is then coated with a hard resin material. The hard resin material is then overcoated with a resilient material to provide shock protection and strain relief. The connector may be placed in a housing, which is covered and sealed to form a water-tight seal between the cover and the housing.

Abstract: A wet end termination for a towed cable. An elongated cylindrical structure includes a bellows surface that is extendable under towing force. The cylindrical structure includes opposed tapered ends, the rear ends encapsulated the region of splice between the optical fiber conductor of the cable and the optical circuit of the towed array.

Abstract: A protected fiber optical splice and a method for making the protected splice. The protective structure encapsulates first and second spliced optical fibers. The fibers are preferably fusion spliced. The protective structure includes a rigid tube surrounding the splice and its adjacent regions of the spliced fibers. A plastic such as an epoxy or moldable plastic is injected into the tube between the substantially axially centered fibers and splice, and the interior wall of the tube. Two molding fixtures are preferably surrounding the two ends of the tube, for injecting the moldable plastic into the tube and for shaping the portions of the structure external to the the tube ends.

Abstract: A thermal reactor for epitaxial deposition on a wafer comprises a double-dome vessel and dual heat sources. Each heat source comprises inner and outer circular arrays of infrared lamps. Circumferential heating uniformity is assured by the cylindrical symmetry of the vessel and the heating sources. Radial heating uniformity is provided by independent control of inner and outer heating arrays for both the top and bottom heat sources. The relative temperatures of wafer and susceptor are controlled by adjusting relative energies provided by the upper and lower heat sources so that backside migration. Reduced pressure operation is provided for by the convex top and bottom domes. Due to the provided control over transmitted energy distribution, a susceptor can have low thermal mass so that elevated temperature can be achieved more quickly and cooling can be facilitated as well. This improves throughput and reduces manufacturing costs per wafer. Reagent gas introduction can be axial or radial as desired.

Abstract: A counter electrode structure of a transition metal electrochromic compound for use in an electro-optical device, which is useful in control of visible and infrared absorption by windows, in data display devices and the like, typically comprising in sandwich arrangement a pair of electrodes, and disposed therebetween, a layer of transition metal electrochromic compounds and a semi-solid highly conductive sulfuric acid gel electrolyte, one of the electrodes being said counter electrode. The gel exhibits good conductivity, stability and compatibility with the electrochromic layers. The present counter electrode is more efficient and has a longer lifetime.

Abstract: A counter electrode structure of a transition metal electrochromic compound for use in an electro-optical device, which is useful in control of visible and infrared absorption by windows, in data display devices and the like, typically comprising in sandwich arrangement a pair of electrodes, and disposed therebetween, a layer of transition metal electrochromic compounds and a semi-solid highly conductive sulfuric acid gel electrolyte, one of the electrodes being said counter electrode. The gel exhibits good conductivity, stability and compatibility with the electrochromic layers. The present counter electrode is more efficient and has a longer lifetime.