Abstract:
A method of making a glass optical fiber having a core surrounded by cladding containing diametrically opposed regions of different TCE than the cladding. Three manufacturing techniques are disclosed. (1) A first glass rod having core and cladding glass is placed centrally in a glass tube. Rods of glass having a TCE different from that of the cladding glass are put on opposite sides of the first rod. Rods of cladding glass are placed in the interstices. (2) A soot preform is deposited on a rotating mandrel. In one embodiment, mandrel rotation is halted to deposit one longitudinally extending region and then rotated 180.degree. to deposit the other such region. In a modified embodiment the mandrel continuously rotates and the deposition burner is continuously supplied with reactant gas for forming a base glass and is also provided with pulses of a reactant gas for modifying the base glass to form the diametrically opposed regions. (3) A CVD process is modified by inserting a pair of tubes into the substrate tube when the longitudinally extending regions are to be deposited. There is passed between the first tube and the pair of tubes a gas which reacts to form particles of a base glass and there is passed through the pair of tubes another gas which reacts to form dopant glass particles which combine with base glass particles to form longitudinal strips of doped base glass within the tube.
Abstract:
This invention is directed to the production of fused silica-containing glass articles of large cross section or diameter wherein at least a surface layer thereof exhibits very high optical quality. The method involves depositing via flame hydrolysis/oxidation reaction a layer of fused silica-containing soot onto a supporting bait, essentially immediately thereafter applying a source of heat concentrated uniformly across the breadth of the soot deposit, but focused only over a relatively small area thereof, to raise the temperature within that area sufficiently to uniformly consolidate the soot in that area into a non-porous glass, and then cooling the glass to room temperature.
Abstract:
A single mode optical waveguide is fabricated in a manner such that the core thereof is subjected to a stress-induced birefringence. A hollow intermediate product is formed by depositing layers of cladding and core glass on the inner surface of a substrate tube. Opposite sides of the intermediate product are heated to cause it to collapse into a solid preform foreproduct having an oblong cross-section. A layer of flame hydrolysis-produced soot having a circular outer surface is deposited on the preform foreproduct and is consolidated to form a dense glass cladding layer thereon. The TCE of the outer cladding layer is different from that of the preform foreproduct on which it is deposited so that when the resultant preform is drawn into a fiber, a stress-induced birefringence exists in the core.
Abstract:
A method of forming a preform or blank for a high bandwidth gradient index optical filament, the preform itself and the resulting optical filament is disclosed. The preform which ultimately forms the optical filament includes a barrier layer between a tubular starting member which comprises the cladding and the core, the index of refraction of the barrier layer being equal to or less than the index of refraction of the tubular starting member; there being no step increase in the index of refraction of the barrier layer at the barrier layer-cladding interface nor of the core at the core-barrier layer interface of the optical filament. The barrier layer is formed from a base glass, a first dopant B.sub.2 O.sub.3, and at least one other dopant which is maintained substantially constant in the barrier layer and then gradually varied during the formation of the core. The quantity of B.sub.2 O.sub.3 is also maintained substantially constant in the barrier layer but then gradually decreased during the formation of the core.
Abstract translation:公开了一种形成用于高带宽梯度折射率光纤的预成型件或坯料的方法,预成型件本身和所得到的光纤。 最终形成光纤的预成型件包括在包括包层和芯之间的管状起始构件之间的阻挡层,阻挡层的折射率等于或小于管状起始构件的折射率; 阻挡层 - 包层界面处的阻挡层的折射率和光纤的芯阻挡层界面处的芯的折射率没有增加。 阻挡层由基底玻璃,第一掺杂剂B 2 O 3和至少一种其它掺杂剂形成,其在阻挡层中保持基本上恒定,然后在芯的形成期间逐渐变化。 在阻挡层中B 2 O 3的量也保持基本恒定,但在芯的形成期间逐渐降低。
Abstract:
A method is provided that includes: forming a low-index trench region (112) with a first density; forming an inner barrier layer (116a) comprising silica around the trench region at a second density greater than the first density; depositing silica-based soot around the first barrier layer to form an overclad region (114) at a third density less than the second density; inserting a core cane (102) into a trench-overclad structure; forming an outer barrier layer (116b) comprising silica in an outer portion of the overclad region at a fourth density greater than the third density; flowing a down dopant-containing gas through the trench-overclad structure (110) to dope the trench region with the down dopant, and wherein the barrier layers (116a,116b) mitigate diffusion of the down-dopant into the overclad region (114); and consolidating the trench-overclad and the core cane. A method of making a consolidated trench-overclad structure with inner and outer barrier layers is also provided.
Abstract:
An optical fiber package is described comprising a light transmitting core having a core diameter, a coating layer surrounding the core, and wherein the amount of chlorine in the light transmitting core region is homogeneous and comprises at least 3000ppm. The fiber package is such that the optical fiber core exhibits a reduction in the hydrogen induced attenuation losses. A method for fabricating the optical fiber package is also disclosed, which comprises carrying out chemical vapour deposition reactions in a substrate tube and collapsing the tube in a C12 atmosphere to form a preform.
Abstract:
La présente invention concerne une fibre optique résistante aux radiations comprenant au moins un cœur et au moins une première gaine entourant ledit cœur. Selon l'invention, ledit cœur comprend une matrice de phosphosilicate, ledit cœur étant dopé terre-rare choisi parmi l'erbium, l'ytterbium, le néodyme, le thulium ou codopé erbium-ytterbium ou thulium- holnniunn et ledit cœur est codopé au cérium. L'invention concerne également un procédé de durcissement aux radiations d'une fibre optique comprenant un cœur à matrice de phospho- silicate, ledit cœur étant dopé terre-rare choisi parmi l'erbium, l'ytterbium, le néodyme, le thulium ou codopé erbium-ytterbium ou thulium-holmium, et comprenant une étape de codopage au cerium du cœur de ladite fibre.
Abstract:
Die Erfindung betrifft eine Lichtleitfaser, insbesondere eine Laserfaser, enthaltend einen dotierten Glasfaserkern (1) und ein den Glasfaserkern umgebendes Cladding (2) mit einem vom Faserkern nach außen abnehmenden Brechzahlprofil. Die Lichtleitfaser zeichnet sich durch mindestens eine zwischen dem Glasfaserkern und dem Cladding angeordnete, mechanische Spannungen zwischen dem Glasfaserkern und dem Cladding reduzierende Zwischenschicht (3; 4, 5) aus. Bei einer zweckmäßigen Ausführungsform weist diese eine einen stufenförmigen mechanischen Spannungsverlauf zwischen dem Glasfaserkern und dem Cladding sichernde Zwischenschichtdotierung und eine einer brechzahlerhöhenden Wirkung der Zwischenschichtdotierung entgegenwirkende brechzahlreduzierende Zwischenschicht-Kodotierung auf. Die Erfindung betrifft weiterhin ein Aufbringen mindestens einer dotierten Barriereschicht auf einen Kernbereich bei der Preformfertigung mit dem Ziel, die Diffusion von speziellen Kerndotanden aus dem Kern während des Kollabierprozesses zu vermeiden und die Diffusion von speziellen Dotanden zwischen der Barriereschicht und der Kernschicht zu ermöglichen.