Abstract: 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 ?m and 15 ?m, 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 10?5 and has applications in dual-use technologies including laser power delivery, sensing and imaging.

Abstract: 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.

Abstract: 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.

Abstract: Disclosed is a method of flash sintering a sample composed of ceramic particles by providing laser energy to change the electrical properties of the ceramic material. The processes and systems disclosed herein do not require large heating equipment like a furnace allowing for a portable system of repairing ceramic materials in the field.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A high optical quality multicomponent chalcogenide glasses without refractive index perturbations due to striae, phase separation or crystal formation made 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.

Abstract: 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.

Abstract: A method for producing nanostructured, hydrophilic, transmissive, anti-reflective surfaces is described. The method for providing a hydrophilic surface includes steps of providing a substrate that is transmissive in at least one wavelength in the infrared to ultraviolet range of the electromagnetic spectrum and comprises at least one surface including nanostructures of a size smaller than the at least one wavelength; and functionalizing the at least one surface with hydroxyl groups thereon. This method provides devices having excellent transmittance and anti-reflectance properties and which are resistant to seawater.

Abstract: 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.

Abstract: 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.

Abstract: 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 ?m and 15 ?m, 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 10?5 and has applications in dual-use technologies including laser power delivery, sensing and imaging.

Abstract: 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 ?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.

Abstract: Disclosed is a method of flash sintering a sample composed of ceramic particles by providing laser energy to change the electrical properties of the ceramic material. The processes and systems disclosed herein do not require large heating equipment like a furnace allowing for a portable system of repairing ceramic materials in the field.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.