USA As Represented by Secretary of the Navy

Other

Shyam S Bayya

Jasbinder Singh Sanghera

Ishwar Dayal Aggarwal

Guillermo R Villalobos

Woohong Kim

Daniel Joseph Gibson

Vinh Q Nguyen

Bryan Sadowski

Mikhail Kotov

Michael Hunt

L Brandon Shaw

Rafael R Gattass

Daniel L Rhonehouse

Gryphon A Drake

Geoff Chin

Leslie Brandon Shaw

Colin C Baker

Geoffrey Chin

Pablo C Pureza

Barry B Harbison

Brian A Cole

Robert E Miklos

Reza Mossadegh

Benjamin Rock

Jesse A Frantz

Jason D Myers

Steven R Bowman

Frederic Hau Kung

Jay N Vizgaitis

Alex E Moser

John M Jewell

Jas S Sanghera

Cathy S Scotto

Christopher G Brown

Guollermo R Villalobos

Guillermo E Villalobos

This application relates generally to an optical fiber for the delivery of infrared light where the polarization state of the light entering the fiber is preserved upon exiting the fiber and the related methods for making thereof. The optical fiber has a wavelength between about 0.9 μm and 15 μm, comprises at least one infrared-transmitting glass, and has a polarization-maintaining (PM) transverse cross-sectional structure. The infrared-transmitting, polarization-maintaining (IR-PM) optical fiber has a birefringence greater than 10and has applications in dual-use technologies including laser power delivery, sensing and imaging.

Infrared-transmitting, polarization-maintaining optical fiber and method for making

The present invention provides a method for making a high strength, small grain size ceramic having a transgranular fracture mode by rapid densification of a green body and subsequent cooling of the densified ceramic. The ceramic may include dislocations, defects, dopants, and/or secondary phases that are formed as a result of the process and resulting in stress fields capable of redirecting or arresting cracks within the material. This ceramic can maintain transparency from ultraviolet to mid-wave infrared.

High strength ceramics with novel fracture mode

The present invention provides for synthesizing high optical quality multicomponent chalcogenide glasses without refractive index perturbations due to striae, phase separation or crystal formation using a two-zone furnace and multiple fining steps. The top and bottom zones are initially heated to the same temperature, and then a temperature gradient is created between the top zone and the bottom zone. The fining and cooling phase is divided into multiple steps with multiple temperature holds.

Manufacturing process for striae-free multicomponent chalcogenide glasses via multiple fining steps

The present invention provides a method for making a high strength, small grain size ceramic having a trans-granular fracture mode by rapid densification of a green body and subsequent cooling of the densified ceramic. The ceramic may include dislocations, defects, dopants, and/or secondary phases that are formed as a result of the process and resulting in stress fields capable of redirecting or arresting cracks within the material. This ceramic can maintain transparency from ultraviolet to mid-wave infrared.

A method for making high optical quality multicomponent chalcogenide glasses without refractive index perturbations due to striae, phase separation or crystal formation using a sealed ampoule with chemical components enclosed inside, a two-zone furnace, a convection heating/mixing step, and multiple fining steps. Initially, the sealed ampoule is oriented vertically within the two-zone furnace and heated to melt the chemical components contained within, and a temperature gradient is created between the top zone and the bottom zone such that the bottom zone has a higher temperature. This temperature gradient causes convection currents within the viscous liquid until it is sufficiently mixed due to the convective flow. Then the temperature gradient is reversed such that the top zone now has a higher temperature and the convective flow ceases. The furnace temperatures are then reduced over a period of time, with holds at multiple temperatures for fining and cooling to form a solid glass.

Manufacturing process for striae-free multicomponent chalcogenide glasses via convection mixing

An optical fiber with multiple openings made from the steps comprising fabricating an extrusion die using at least one additive manufacturing technique such that the extrusion die has a first set of plurality of channels that combine inside the die into a second set of plurality of channels with a different set of shapes and sizes, extruding a glass through the extrusion die, forming a fiber optic preform having a plurality of longitudinal openings that run the entire length of the fiber optic preform, attaching a barrier layer to the fiber optic preform to form a series of channels to which pressure can be applied by a gas, wherein each channel has a pressure that is independently controlled, and stretching the fiber optic preform at an elevated temperature into an optical fiber with multiple openings.

Optical fibers with multiple openings from additive manufacturing

A transparent composite armor is made of tens to hundreds or even thousands of thin layers of material each with a thickness of 10-500 &#x3bc;m. An appropriate amount of impedance mismatch between the layers causes some reflection at each interface but limit the amplitude of the resulting tensile wave below the tensile strength of the constituent materials. The result is an improvement in ballistic performance and that will result is a significant impact in reducing size, weight, and volume of the armor.

Shockwave controlled ballistic protection

A method of purifying a spinel powder includes contacting a spinel powder with an acid solution to form an acid-washed spinel composition and contacting the acid-washed spinel composition with a basic solution to form a purified composition. The purified powder is suited to formation of low-absorption shaped bodies, such as windows for high intensity laser devices.

Low absorption spinel formed by acidic and basic treatments

The invention relates to rare-earth-doped ternary sulfides. The rare-earth-doped ternary sulfides may be used as an active material for mid-wave infrared and long-wave infrared lasers and amplifiers. Methods for producing laser materials including rare-earth-doped ternary sulfides, as well as lasers and amplifiers incorporating the laser materials, are also provided.

Rare-earth-doped ternary sulfides for mid-wave and long-wave IR lasers

A method of making an optical fiber with multiple openings comprising the steps of fabricating an extrusion die using additive manufacturing such that the extrusion die has a plurality of channels that combine inside the die into another set of channels, extruding a glass, forming a fiber optic preform having a plurality of longitudinal openings that run the entire length, attaching a barrier layer for pressure application, and stretching the preform into an optical fiber with multiple openings. An extrusion die comprising an additive manufactured material, having a proximal side having openings and having a distal side having openings, wherein the openings of the proximal side are of feed channels, wherein the openings of the distal side are of forming channels, and wherein in side the body of the die, two of the feed channels combine the forming channels.

Method of making optical fibers with multiple openings

Systems and methods are provided for mechanically encapsulating an infrared transmitting optical fiber, removing any power coupled to the cladding of the infrared optical fiber, and bridging the thermal properties between the optical fiber and the mechanical ferrule used. Embodiments of the present disclosure have several advantages over prior systems. For example, in an embodiment, the transmitting ferrule does not require epoxy to mount the fiber to the ferrule, isolates the front face of the fiber, and allows for high power to be incident on the connector without damage by reducing the thermal induced stress and managing any stray light coupled to the core.

Infrared transmitting epoxyless fiber optic connector and fiber optic cable

A method for making a gradient index infrared transmitting optic by thermally treating a preform, where the preform comprises two or more infrared transmitting glasses having different compositions and optical properties, where there is an interface between adjacent glasses, where during the thermal treatment one or more chemical elements from the glasses diffuses through one or more interface resulting in a diffused gradient index optical element comprising a gradient in the chemical element concentration, and where the optical element has a gradient in refractive index and dispersion. Also disclosed is the related infrared transmitting optical element made by this method.

Gradient index infrared transmitting optics and method for making same

The present invention provides a method for synthesizing high optical quality multicomponent chalcogenide glasses without refractive index perturbations due to striae, phase separation or crystal formation using a two-zone furnace and multiple fining steps. The top and bottom zones are initially heated to the same temperature, and then a temperature gradient is created between the top zone and the bottom zone. The fining and cooling phase is divided into multiple steps with multiple temperature holds.

A method for bonding infrared transmitting glasses into an optical element without interlayer voids by stacking at least two different infrared transmitting glasses inside a vessel where each glass has a different refractive index, a different dispersion, or both, and where the glasses all have similar viscosities, thermal expansion coefficients, and glass transition temperatures; placing a weight on top of the stack; applying a vacuum to the vessel; applying an isostatic pressure of at least 1500 psi; and after releasing the isostatic pressure, annealing at a temperature within 10&#xb0; C. of the glass transition temperature at a pressure between 0 and 1000 psi. Applying the vacuum, applying the isostatic pressure, and annealing are done sequentially and with no intermediate transitions to ambient temperature or pressure. Also disclosed is the related optical element made by this method.

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Ashburn, VA, United States of America

Shyam S Bayya