Abstract:
PROBLEM TO BE SOLVED: To provide an optical fiber having a large effective cross-sectional area (A eff ), in which the concentration of a rare earth element is easily controlled and generation of a nonlinear optical effect is effectively suppressed in a fiber amplifier or a fiber laser, and to provide a method for producing an optical fiber preform suitable for the production of the optical fiber. SOLUTION: The method for producing an optical fiber preform in which a rare earth element is added into the core comprises: a step of depositing fine glass particles which are mainly composed of silicon dioxide within a quartz tube by a MCVD method; a step of adding the rare earth element and aluminum into the fine glass particles within the quartz tube by an immersion method; a step of heating the quartz tube while allowing a phosphorus-containing gas to flow into the quartz tube, so as to sinter the fine glass particles within the quartz tube while adding phosphorus thereinto; and a step of heating and collapsing the quartz tube, into which the rare earth element, the aluminum and the phosphorus have been added. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
The X-ray opaque glass is characterized by a composition, in mol %, of SiO2, 75-98; Yb2O3, 0.1 to 40; and ZrO2, 0 to 40. Preferred embodiments of the glass are free of Al2O3 and B2O3. The glass is produced from the glass batch by melting at a temperature of at least 1500° C. in an iridium or iridium alloy vessel with the assistance of high-frequency radiation. In preferred embodiments of the glass production process at least one raw material ingredient is present in the batch as a nanoscale powder. The glass is useful in dental applications, optical applications, and biomedical applications, or for photovoltaics, or as a target material in PVD processes.
Abstract:
An ytterbium-doped optical fiber of the present invention includes: a core which contains ytterbium, aluminum, and phosphorus and does not contain germanium; and a cladding which surrounds this core. The ytterbium concentration in the core in terms of ytterbium oxide is 0.09 to 0.68 mole percent. The molar ratio between the phosphorus concentration in the core in terms of diphosphorus pentoxide and the above ytterbium concentration in terms of ytterbium oxide is 3 to 30. The molar ratio between the aluminum concentration in the core in terms of aluminum oxide and the above ytterbium concentration in terms of ytterbium oxide is 3 to 32. The molar ratio between the above aluminum concentration in terms of aluminum oxide and the above phosphorus concentration in terms of diphosphorus pentoxide is 1 to 2.5.
Abstract:
Bei einem bekannten Verfahren zur Herstellung von Seltenerdmetall-dotiertem Quarzglas sind folgende Verfahrensschritte vorgesehen: (a) Bereitstellen eines Rohlings aus dem mit Seltenerdmetall dotierten Quarzglas, und (b) Homogenisieren des Rohlings, indem dieser in einer Heizzone zonenweise erweicht und dabei die erweichte Zone längs einer Rotationsachse tordiert wird. Bei einigen Seltenerdmetallen wird jedoch eine Verfärbung des Quarzglases beobachtet, was auf eine nicht vorhersehbare und unerwünschte Veränderung der chemischen Zusammensetzung oder möglicherweise auf eine inhomogene Verteilung der Dotierstoffe hinweist. Um diesen Nachteil zu vermeiden und ein modifiziertes Verfahren angegeben, das die Herstellung von Seltenerdmetall-dotiertem Quarzglas mit reproduzierbaren Eigenschaften gewährleistet, wird erfindungsgemäß vorgeschlagen, dass der Rohling beim Homogenisieren gemäß Verfahrensschritt (b) unter Einwirkung eines oxidierend wirkenden oder eines neutralen Plasmas erweicht wird.
Abstract:
An active optical fibre, including: a core; an inner cladding substantially surrounding the core, whereby the core and the inner cladding form an area configured to propagate pump radiation; an outer cladding comprised of at least a third material with at least a third refractive index substantially surrounding the inner cladding, the third refractive index being smaller than the second refractive index, whereby the outer cladding confines pump radiation to the core and the inner cladding; and a coating comprised of a thermally conductive material substantially surrounding the outer cladding, wherein the inner cladding is configured to reduce impact of spatial hole-burning on absorption of the pump radiation as the pump radiation propagates through the active optical fibre, and wherein the thermally conductive material of the coating supports a reduced temperature increase between the area and an outer surface of the coating.
Abstract:
An ytterbium-doped optical fiber of the present invention includes: a core which contains ytterbium, aluminum, and phosphorus and does not contain germanium; and a cladding which surrounds this core. The ytterbium concentration in the core in terms of ytterbium oxide is 0.09 to 0.68 mole percent. The molar ratio between the phosphorus concentration in the core in terms of diphosphorus pentoxide and the above ytterbium concentration in terms of ytterbium oxide is 3 to 30. The molar ratio between the aluminum concentration in the core in terms of aluminum oxide and the above ytterbium concentration in terms of ytterbium oxide is 3 to 32. The molar ratio between the above aluminum concentration in terms of aluminum oxide and the above phosphorus concentration in terms of diphosphorus pentoxide is 1 to 2.5.
Abstract:
The invention relates to a method for producing quartz glass which includes, in addition to doping with rare earth and/or transition metals, the fluorination of the quartz glass. As a result of the described method, the dopants can be prevented from diffusing out during the fluorination. Furthermore, the invention relates to the quartz glass obtainable by means of the method according to the invention and to the use thereof as laser-active quartz glass for producing light-guiding structures and for use in optical applications.