Abstract:
To provide a process for producing an air cladding type optical fiber by a method other than extrusion molding.A process for producing an optical fiber comprising a hollow glass fiber with an optical transmission glass held to extend in its axial direction at its center, which process comprises a step of heating and drawing a glass rod having three or more holes with an equal diameter provided around its center axis to extend in its axial direction where the distance between each hole and the axis is mutually equal and the distance between adjacent holes is mutually equal, and a portion surrounded by such holes will constitute said optical transmission glass, while applying pressure to expand the holes with one end of the rod closed, to form a preform wherein glass between the holes is in a plate form, and subjecting the preform to wire drawing to form an optical fiber in which said optical transmission glass is held by plate glass.
Abstract:
The present invention relates to microspheres (i.e., beads) that comprise titania and bismuth oxide. The glass microspheres further comprise zirconia. The invention also relates to retroreflective articles, and in particular pavement markings, comprising such microspheres.
Abstract:
In one aspect, the invention features a fiber waveguide having a waveguide axis, including a first portion extending along the waveguide axis, and a second portion different from the first portion extending along the waveguide axis surrounding the first portion, wherein at least one of the first and second portions comprises a chalcogenide glass selected from the group consisting of Selenium chalcogenide glasses and Tellurium chalcogenide glasses, both the first and second portions have a viscosity greater than 103 Poise at some temperature, T, and the fiber waveguide is a photonic crystal fiber.
Abstract:
An optical fiber having a length can include a core and at least one cladding disposed about the core, where the one cladding can comprise at least first volumetric regions having a first refractive index n1 and second volumetric regions having a second refractive index n2, different from n1, and the first and second volumetric regions in any cross-section taken through the fiber can be randomly intermingled with one another, where the random intermingling of the first and second volumetric regions changes with changes in the location of the cross-section along the length of the fiber.
Abstract:
An object of the present invention is to provide a transparent ceramics which exhibits favorable slope efficiency well comparable to that of a single crystal when employed in solid lasers, yet having a uniform quality and internally free from pores, foreign matters, or granular structures. Another object of the present invention is to provide a production method therefor. The above problems have been overcome by a transparent YAGnullceramics (YAG: Y3Al5O12) the physical properties thereof is improved by doping a metallic element, provided that the concentration of the doped metallic elements is in a range of from 0.1 to 20% by weight, that the concentration of nitrogen is 500 ppm or lower, that said ceramics has pores and foreign matters accounting for less than 100 mm2 per 100 cm3 as expressed by their projected area, and that it has an internal transmittance for visible radiations of 50 %/cm of higher. The metallic element for doping the YAGnullceramic is Nd.
Abstract:
The present invention is directed to the preparation of in-situ formation of a series of glass-ceramic composites by the Self-propagating High temperature Synthesis (SHS) technique with advantages of processing simplicity as well as the potential of cost savings. The materials produced by the technique contain crystalline TiB2 phase and have either a pure glassy matrix or a glass matrix with partial devitrification based on the Al2O3—CaO system. The materials can potentially be used for infrared light transmission and for other high temperature applications. These materials can also be produced with relatively high porosity.
Abstract:
The present invention is generally directed to a photonic bad gap fiber and/or fiber preform with a central structured region comprising a first non-silica based glass and a jacket comprising a second non-silica based glass surrounding the central structured region, where the Littleton softening temperature of the second glass is at least one but no more than ten degrees Celsius lower than the Littleton softening temperature of the first glass, or where the base ten logarithm of the glass viscosity in poise of the second glass is at least 0.01 but no more than 2 lower than the base ten logarithm of the glass viscosity in poise of the first glass at a fiber draw temperature. Also disclosed is a method of making a photonic bad gap fiber and/or fiber preform.
Abstract:
A method and apparatus for making a substantially void-free preform for a microstructured optical fiber using a one-step process is provided. A preform is prepared from specialty glasses using a direct extrusion method. A die for use with the direct extrusion method is also provided, and a method for drawing the preform into a HC-PBG fiber for use in transmitting infra-red wavelength light is also provided. The preform comprises an outer jacket made of solid glass, a cladding having a plurality of air holes arranged in a desired pattern within the jacket, and a core which is hollow.
Abstract:
Disclosed is an amplifying optical fiber having a central core and an optical cladding surrounding the central core. The central core is based on a silica matrix that includes nanoparticles, which are composed of a matrix material that includes doping ions of at least one rare earth element. The amplifying optical fiber can be employed, for example, in an optical amplifier and an optical laser.
Abstract:
A fabrication method of an optical fiber using as a core material tellurite glass. The method includes a first process of molding a tellurite glass melt into a mold, the mold having a plurality of convex portions defining an inner wall, which portions run parallel to each other in a longitudinal direction in order to make a polygon columnar glass preform, and a second process of inserting the glass preform into a cylindrical jacket tube made of tellurite glass and carrying out fiber-drawing under pressure so as to maintain or enlarge air holes which are gaps generated between the glass preform and the jacket tube.