United Technologies Corporation

Polaroid Corporation

American Optical Corporation

Other

USA As Represented by Secretary of the Navy

Exxon Research and Engineering Company

Better Environmental Development Corporation

Elias Snitzer

Gerald Meltz

William H Glenn

Donald R Uhlmann

Nori Y Chu

Richard J Hovey

James F Bacon

Joseph T Fournier, Jr

Farhad Hakimi

Richard P Tumminelli

Hong Po

James R Dunphy

David A Krohn

Amaresh Mahapatra

William W Morey

Peter E Raber

Robert E Wisnieff

Roy W Miller

Donald E Anschutz

Edward V Fox, Jr

Shaoul Ezekiel

An integrated optics print head includes an array of indepenedently driven semiconductor lasers disposed on a common substrate with their outputs coupled to an integrated waveguide structure. The integrated waveguide structure includes a multiplicity of 'S' shaped, low-loss waveguides which have substantially the same length. Further, in order to reduce crosstalk, the region of the waveguide structure at the output where all the waveguides are in close proximity is made as short as possible while maintaining a parallel relation between the waveguide outputs.

Integrated optic print head

A method for fabricating optical fibers having a rare-earth doped core and a fused silica cladding includes inserting a rare-earth doped soft glass rod into a fused silica tube, the ratio of the outer diameter (OD) to the inner diameter (ID) of the fused silica tube being at least 2 and as large as 50; heating the rod and tube combination in a furnace to selectively volatilize volatile constituents of the soft glass rod which are responsible for the low softening point so that the final composition of the core consists predominantly of SiO.sub.2 and the desired dopants such as rare earths, alkaline earths or other low vapor pressure materials; and drawing the perform into an optical fiber.

Selective volitization method for preparing fiber optics

Apparatus for coupling radiation into a single-mode core of an optical fiber laser has a single-mode core disposed within a relatively large, multimode cladding at a location which is displaced from the center of the cross-section of the cladding. The cladding is surrounded by a further layer to prevent radiation from propagating out of the cladding. In addition, the apparatus preferably has slight bends to enhance the coupling of radiation from the cladding into the single-mode core. A further embodiment has a single-mode fiber laser disposed in a relatively large, multimode, slab cladding which, in turn, is surrounded by another cladding to prevent radiation from propagating out of the large cladding.

Optical fiber lasers and amplifiers

An optical fiber has a dielectric periodic index of refraction phase grating established in its core by intense angled application of several transverse beams of ultraviolet light, enabling the establishment of a distributed, spatially resolving optical fiber strain gauge.

Method for impressing gratings within fiber optics

A distributed, spatially resolving optical fiber strain gauge in which the core of the optical fiber is written with periodic grating patterns effective for transmitting and reflecting light injected into the core. Spectral shifts in the transmitted and reflected light indicate the intensity of strain or temperature variations at positions of the grating corresponding to the associated wavelengths of injected light.

Distributed, spatially resolving optical fiber strain gauge

An optical fiber laser comprising a nearly pure fused silica glass, neodymium doped active core within a cavity in the form of a single mode optical fiber. The gain cavity is end pumped at a nominal wavelength of 0.8 microns and its length and neodymium concentration are adjusted to maximize pump absorption and minimize concentration quenching. Dichroic mirrors are preferably integrally formed on ends of the cavity and have reflection characteristics selected so that the laser has an output at a nominal wavelength of 1.06 microns.

Ion doped, fused silica glass fiber laser

An optical fiber laser comprising a gain cavity in the form of a single mode optical fiber with integrally formed dichroic mirror end sections to provide feedback. The fiber core comprises a host material of silicate glass preferably doped with 0.01 to 1 weight percent of just erbium oxide as a lasing medium. The laser is end pumped at approximately 1.49 micrometers with a laser diode, preferably InGaAsP, and has an output at 1.54 micrometers.

Optical fiber laser

A method of establishing a dielectric periodic index of refraction phase grating upon the core of an optical waveguide by intense angled application of several transverse beams of ultraviolet light, enabling the establishment of a distributed, spatially resolving optical fiber strain gauge.

A fiberscope for the viewing of the interior of an operating engine combur is provided with a fused coherent fiber bundle as an image conduit to transmit the image of said interior through the wall of the combustor. Illumination may be provided through the use of a second optical fiber or bundle and a coherent light source aligned with the image conduit.

Combustor fiberscope

An optical amplifier particularly suitable for use in amplifying signals carried on optical fiber in a select communication band. The amplifier comprises a resonant optical waveguide cavity which has a core containing an active gain material with given absorption and fluorescence spectrums. The gain material is of the type that preferably has at least two different emission bands originating from the same energy level with one of the emission bands encompassing the select communication band. The cavity is structured to resonate wavelengths in both emission bands, but with a higher combination of cavity Q and gain coefficient per excited ion for wavelengths in the emission band not corresponding to the select communication band so that, when pumped, the cavity first lases at this band. The lasing action causes the atomic population of the gain material corresponding to the communication band to remain at a stable constant level where it is available to uniformly amplify by stimulated emission optical signals introduced into the cavity.

Optical amplifier

An optical fiber laser comprising a gain cavity in the form of a single mode optical fiber with integrally formed reflective end sections for provision of feedback. One end section is an etalon for modifying the gain cavity resonant characteristics and intensity modulation, and the other end section is used to alter gain cavity effective length to tune and frequency modulate. The emission spectrum of the laser gain material, which is preferably neodymium oxide incorporated in a silicate glass core, along with the etalon section reflection, pump energy level, and gain cavity length cooperate so that lasing takes place over just a single line of narrow width or over more than one line within a narrow band. Electro-optic material in the end sections permit output frequency and amplitude to be selectively activated in response to the application of applied voltages.

An optical strain measuring arrangement including an optical waveguide comprising first and second cores fixedly mounted with respect to a mechanical structure to be monitored, and a detection system for relating the contrast in light intensity emerging from said cores to a range of wavelengths to establish an indication of strain along the range of the optical waveguide.

Spatially resolving fiber-optic crosstalk strain sensor

A super-radiant light source having an output with a low temporal coherence well suited, for example, to optical inertial sensor applications, includes a single mode optical waveguide such as an optical fiber having its core doped with an active laser material, such as neodymium. Pump light is coupled into the optical fiber at an intensity sufficient to produce a significant amplification of the spontaneous emission. The reflectivity at the exit end of the fiber is low enough so that even with a high gain for the light in one traverse through the fiber, the fiber is operated well below threshold for laser oscillation. The resulting emission is of high intensity, but has a low temporal coherence. In one form, the pump light is coupled into one end of the fiber and a dichroic filter is interposed in the light path between the pump light and the optical fiber to pass pump light into the core and reflect the spontaneous emission of the active material back into the core and toward the output.

Super radiant light source

A method of bonding a plurality of thermally stable high strength graphite fiber reinforced glass matrix composite pieces is described. The process comprises applying to the surfaces to be bonded at least one layer of a metal which is highly adherent to the composite and the solder and is oxidatively stable. A tie layer may be used between the composite bond surface and the metal layer to better bond the metal layer to the composite. Following application of the metal layer, the composite pieces are stacked with the metal layers facing each other and a solder layer in between. The temperature of the assembly is raised to melt the solder and form the bond. The melting temperature of the solder and the metal layers are chosen so as to be higher than the use temperature of the bonded composite. A bonded composite article thus formed is also described.

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Wellesley, MA, United States of America

Elias Snitzer