Abstract: A method of producing a microstructured optical fiber is disclosed. The method includes providing a preform and drawing the preform. The preform has a center axis, a length and a first end and a second end and has at least one longitudinal hole extending lengthwise. The method includes inserting a first end of a pressure tube into the hole of the preform at the first end of the preform and subjecting the hole of the preform to a controlled pressure via the pressure tube during the drawing.

Abstract: A microstructured optical fiber includes a core region and a cladding region which surrounds the core region. The cladding region includes a plurality of cladding features within a cladding background material, wherein the cladding region includes an inner cladding region with at least one inner ring of cladding features and an outer cladding region with at least three outer cladding rings of outer cladding features. The inner cladding features have a first characteristic diameter and the outer cladding region includes a plurality of outer cladding features having a characteristic diameter smaller than the first characteristic diameter. The first characteristic diameter is at least about 10% larger than an average diameter of the outer cladding features and the core region has a diameter of at least about 2 ?m.

Abstract: The invention concerns a Photonic Crystal Fiber (PCF) a method of its production and a supercontinuum light source comprising such PCF. The PCF has a longitudinal axis and comprises a core extending along the length of said longitudinal axis and a cladding region surrounding the core. At least the cladding region comprises a plurality of microstructures in the form of inclusions extending along the longitudinal axis of the PCF in at least a microstructured length section. In at least a degradation resistant length section of the microstructured length section the PCF comprises hydrogen and/or deuterium. In at least the degradation resistant length section the PCF further comprises a main coating surrounding the cladding region, which main coating is hermetic for the hydrogen and/or deuterium at a temperature below Th, wherein Th is at least about 50° C., preferably 50° C.<Th<250° C.

Abstract: A hollow core photonic crystal fiber (PCF) comprising an outer cladding region and 7 hollow tubes surrounded by the outer cladding region. Each of the hollow tubes is fused to the outer cladding to form a ring defining an inner cladding region and a hollow core region surrounded by the inner cladding region. The hollow tubes are not touching each other, but are arranged with distance to adjacent hollow tubes. The hollow tubes each have an average outer diameter d2 and an average inner diameter d1, wherein d1/d2 is equal to or larger than about 0.8, such as equal to or larger than about 0.85, such as equal to or larger than about 0.9. Also a laser system is disclosed.

Abstract: The invention comprises a photonic crystal fiber (PCF) assembly comprising a PCF and at least one ferrule structure. The PCF has a center axis and comprises a core region and a cladding region and a first fiber end section with a first fiber end. The ferrule structure has a center axis and is mounted to the first fiber end section. The ferrule structure comprises an inner ferrule arrangement and an outer ferrule arrangement surrounding the first fiber end section. The inner ferrule arrangement comprises an inner ferrule front section proximally to the first fiber end and an inner ferrule rear section distally to the first fiber end, and each of the inner ferrule sections have an inner diameter and in at least a length thereof fully surrounds the PCF. The inner ferrule rear section is anchored in an anchor length section to the first fiber end section and the inner ferrule front section supports the first fiber end section proximally to the first fiber end.

Abstract: The invention concerns a Photonic Crystal Fiber (PCF) a method of its production and a supercontinuum light source comprising such PCF. The PCF has a longitudinal axis and comprises a core extending along the length of said longitudinal axis and a cladding region surrounding the core. At least the cladding region comprises a plurality of microstructures in the form of inclusions extending along the longitudinal axis of the PCF in at least a microstructured length section. In at least a degradation resistant length section of the microstructured length section the PCF comprises hydrogen and/or deuterium. In at least the degradation resistant length section the PCF further comprises a main coating surrounding the cladding region, which main coating is hermetic for the hydrogen and/or deuterium at a temperature below Th, wherein Th is at least about 50° C., preferably 50° C.<Th<250° C.

Abstract: A micro-structured optical fiber suitable for supercontinuum generation, a preform therefor, and a method of production thereof and a supercontinuum light source. The optical fiber includes a core microstructured length section Lcm, which includes a micro-structured core region having at least a first region forming a central part of the core region and a second region surrounding the first region; and a cladding surrounding the core region; wherein the first and second regions are of a first and second silica material, respectively, which differs with respect to composition, and wherein the core region in at least a length part of the core microstructured length section Lcm has a cross sectional diameter Dcm perpendicular to the longitudinal axis which is about 8 ?m or less.

Abstract: The invention relates to a hollow core optical fiber having light guided in a single-mode in the core.

Abstract: The invention relates to a hollow core optical fiber having light guided in a single-mode in the core.

Abstract: The invention relates to an optical fiber having an axial direction and a cross section perpendicular to said axial direction, and a method and preform for producing such an optical fiber. The optical fiber is adapted to guide light at a wavelength ?, and comprises a core region, an inner cladding region surrounding said core region, and at least one of a first type of feature comprising a void and a surrounding first silica material. The core, the inner cladding region and the first type of feature extends along said axial direction over at least a part of the length of the optical fiber. The first silica material has a first chlorine concentration of about 300 ppm or less.