Abstract:
A METHOD OF FORMING AN OPTICAL WAVEGUIDE BY FIRST FORMING A COATING OF GLASS ON THE INSIDE WALL OF A GLASS TUBE, THE GLASS TUBE AND THE FIRST COATING BEING OF SUBSTANTIALLY SIMILAR MATERIAL. THEREAFTER, A SECOND COATING OF GLASS IS APPLIED TO THE INSIDE WALL OF THE GLASS TUBE OVER THE FIRST COATING, SAID SECOND COATING HAVING A PRESELECTED DIFFERENT INDEX OF REFRACTION FROM THAT OF THE FIRST COATING. THE GLASS TUBE AND COATING COMBINATION IS THEREAFTER DRAWN TO REDUCE THE CROSS-SECTIONAL AREA AND TO COLLAPSE THE SECOND AND INNER COATING OF GLASS TO FORM A FIBER HAVING A SOLID CROSS-SECTIONAL AREA. THE COLLAPSED INNER COATING FORMS THE FIBER CORE AND THE FIRST COATING FORMS THE CLADDING FOR THE FIBER WHILE THE EXTERIOR GLASS TUBE PROVIDES STRUCTURAL STRENGTH FOR THE FIBER.
Abstract:
Annealing treatments for modified titania-silica glasses and the glasses produced by the annealing treatments. The annealing treatments include an isothermal hold that facilitates equalization of non-uniformities in fictive temperature caused by non-uniformities in modifier concentration in the glasses. The annealing treatments may also include heating the glass to a higher temperature following the isothermal hold and holding the glass at that temperature for several hours. Glasses produced by the annealing treatments exhibit high spatial uniformity of CTE, CTE slope, and fictive temperature, including in the presence of a spatially non-uniform concentration of modifier.
Abstract:
La présente invention concerne un procédé de fabrication d'une préforme (9) à fibrer pour fibre optique (10) à maintien de polarisation ou fibre polarisante. Selon l'invention, le procédé comprend les étapes suivantes : fabrication d'une préforme rainurée (20) par formation de deux rainures (6, 6') dans une préforme primaire (7) cylindrique de section circulaire et d'axe XX', ladite préforme primaire (7) comprenant un coeur (1) et une gaine (2) disposée autour du coeur (1), lesdites rainures (6, 6') s'étendant parallèlement à l'axe XX' et étant disposées symétriquement par rapport à l'axe XX' ; fabrication de deux barreaux de contrainte comprenant un coeur (3, 3') et une enveloppe externe (4, 4'), le matériau du coeur (3, 3') des barreaux de contrainte ayant un coefficient thermique d'expansion (CTE) différent de celui de la gaine (2) de la préforme primaire (7) et usinage extérieur de l'enveloppe (4, 4') desdits barreaux de contrainte de manière à ce que les dimensions et la forme des barreaux de contrainte usinés (21, 22) soient ajustées aux dimensions et à la forme des rainures (6, 6') ; assemblage de la préforme rainurée (20), des deux barreaux de contrainte usinés (21, 22) insérés respectivement dans chaque rainure (6, 6') de la préforme rainurée (20) et d'un manchon (5) cylindrique de section annulaire entourant ladite préforme rainurée de manière à former une préforme à fibrer (9). L'invention concerne également une fibre optique (10) à maintien de polarisation ou polarisante obtenue par fibrage d'une préforme à fibrer (9).
Abstract:
A holey optical fibre for supporting propagation of light of a wavelength μ, comprises a plurality of cylinders (10) each having a longitudinal axis, the cylinders (10) being separated from each other by regions of a matrix material (20) and having their longitudinal axes substantially parallel to each other. Each cylinder (10) has a diameter, in the plane perpendicular to the longitudinal axis, that is small enough for the composite material of the ensemble of cylinders and matrix material to be substantially optically homogenous in respect of light of wavelength μ.
Abstract:
Provided is an optical fiber having holes extending along the axis whose transmission loss is substantially reduced and the manufacturing method thereof. First, a plurality of through-holes 9 are formed in a preform 5 extending along the preform axis. Subsequently, the preform 5 is heated by heating means 24 in the furnace preferably for 30 minutes or more at a temperature equal to or more than 800 °C while flowing a dry gas in the through-holes 9. As a result, the OH group which exists on the surfaces of the inner walls 5a of the through-holes 9 of the preform 5 is discharged outside the preform. Subsequently, the preform 5 is drawn into an optical fiber.
Abstract:
The present invention provides an optical fiber for use in fiber lasers and amplifiers wherein the optical fiber has a core member surrounded by a cladding member for receiving pump energy and transferring the pump energy to the core member. The optical fiber also has an outer layer surrounding the cladding member. The cladding member has a circular exterior periphery and a predetermined refractive index (n c ). The cladding member has an index modified region that directs light to the core member. The index modified region has a stress field portion with a predetermined refractive index (n s ). The difference between the refractive index of the cladding member and that of the stress field portion (n c - n s ) is within such a range that the stress field portion does not affect the polarization properties of the light traveling in the core. Preferably, the difference between the refractive index of the cladding member and that of the stress field portion (n c - n s ) is less than 10 -4 , and more preferably 10 -5 .
Abstract:
Die Erfindung betrifft ein Verfahren zur Herstellung von optischen Gläsern und Farbgläsern mit Hilfe eines Flüssigphasensinterprozesses aus einem Ausgangsmaterial umfassend wenigstens SiO 2 -Pulver sowie Zusatzstoffe zur Reduzierung der Temperatur des Sinter- und/oder Schmelzprozesses umfassend die nachfolgenden Schritte:
die Ausgangsmaterialien werden in einem flüssigen Medium soweit hierin löslich gelöst und soweit hierin nicht löslich dispergiert ergebend eine Suspension aus dem gelösten und dispergierten Ausgangsmaterial wird einGrünkörper hergestellt der Grünkörper wird getrocknet der getrocknete Grünkörper wird bei Temperaturen geringer als 1200° C, insbesondere im Temperaturbereich von 600° C bis 1200° C flüssigphasengesintert.
Abstract:
A method for making a glass ceramic, optoelectronic material such as a clad optical fiber or other component for use in an optoelectronic device. The method comprises preparing a glass composition batch to yield a precursor glass for a nanocrystalline glass-ceramic that is doped with at least one kind of optically active ion, such as a transition metal or lanthanide element; melting the batch; forming a glass cane; surrounding the cane with a chemically inert cladding material shaped in the form of a tube; drawing a glass fiber from the combined precursor-glass 'cane-in-tube' at a temperature slightly above the liquidus of the precursor glass composition, and heat treating at least a portion of the drawn clad glass fiber under conditions to develop nanocrystals within the core composition and thereby forming a glass ceramic.