Abstract: In a method for manufacturing a preform for drawing a microstructured optical fiber, a core element and multiple sub-elements are arranged extending along the perform. The sub-elements and the core element form a bundle, which is twisted by a specified angle about the longitudinal axis of the bundle, wherein the pattern formed by the cross section of the sub-elements and the cross section of the core element is preserved along a length of the perform. The sub-elements and the core elements are subsequently at least partially fused together by heating the material of which the core element and the sub elements are made of above the transformation point of the material, so as to at least partially eliminate the cavities between the sub-elements, between the sub-elements and the core element, and between the sub-elements and the casing.

Abstract: In a method for manufacturing a preform for drawing a microstructured optical fiber, a core element and multiple sub-elements are arranged extending along the perform. The sub-elements and the core element form a bundle, which is twisted by a specified angle about the longitudinal axis of the bundle, wherein the pattern formed by the cross section of the sub-elements and the cross section of the core element is preserved along a length of the perform. The sub-elements and the core elements are subsequently at least partially fused together by heating the material of which the core element and the sub elements are made of above the transformation point of the material, so as to at least partially eliminate the cavities between the sub-elements, between the sub-elements and the core element, and between the sub-elements and the casing.

Abstract: The invention relates to an apparatus for coupling light into an optical wave guide, a laser system with such an apparatus, and a preform to manufacture the apparatus for coupling light into an optical wave guide with the aid of a pumping fiber to guide the light, whereby the optical wave guide comprises a core with a cladding and an initial length segment with a second length segment immediately connected to it, whose cross section increases in tapered form with respect to the first length segment.

Abstract: The invention relates to an apparatus for coupling light into an optical wave guide, a laser system with such an apparatus, and a preform to manufacture the apparatus for coupling light into an optical wave guide with the aid of a pumping fiber to guide the light, whereby the optical wave guide comprises a core with a cladding and an initial length segment with a second length segment immediately connected to it, whose cross section increases in tapered form with respect to the first length segment.