Abstract: A photonic crystal fiber (PCF) assembly including a PCF and at least one ferrule structure. The PCF includes a core region and a cladding region and a first fiber end section with a first fiber end. The ferrule structure is mounted to the first fiber end section. The ferrule structure includes an inner ferrule arrangement and an outer ferrule arrangement surrounding the first fiber end section. The inner ferrule arrangement includes 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 sections has 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: A photonic crystal fiber (PCF) assembly including a PCF and at least one ferrule structure. The PCF includes a core region and a cladding region and a first fiber end section with a first fiber end. The ferrule structure is mounted to the first fiber end section. The ferrule structure includes an inner ferrule arrangement and an outer ferrule arrangement surrounding the first fiber end section. The inner ferrule arrangement includes 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 sections has 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: A hollow core photonic crystal fiber (PCF) including an outer cladding region and seven 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.

Abstract: A hollow core photonic crystal fiber (PCF) including an outer cladding region and seven 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.

Abstract: A hollow core photonic crystal fiber (PCF) including an outer cladding region and seven 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.

Abstract: A hollow core photonic crystal fiber (PCF) including an outer cladding region and seven 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.

Abstract: A photonic crystal fiber (PCF) assembly including a PCF and at least one ferrule structure. The PCF includes a core region and a cladding region and a first fiber end section with a first fiber end. The ferrule structure is mounted to the first fiber end section. The ferrule structure includes an inner ferrule arrangement and an outer ferrule arrangement surrounding the first fiber end section. The inner ferrule arrangement includes 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 sections has 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: A photonic crystal fiber (PCF) assembly including a PCF and at least one ferrule structure. The PCF includes a core region and a cladding region and a first fiber end section with a first fiber end. The ferrule structure is mounted to the first fiber end section. The ferrule structure includes an inner ferrule arrangement and an outer ferrule arrangement surrounding the first fiber end section. The inner ferrule arrangement includes 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 sections has 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: A hollow core photonic crystal fiber (PCF) including an outer cladding region and seven 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.

Abstract: A photonic crystal fiber (PCF) assembly including a PCF and at least one ferrule structure. The PCF includes a core region and a cladding region and a first fiber end section with a first fiber end. The ferrule structure is mounted to the first fiber end section. The ferrule structure includes an inner ferrule arrangement and an outer ferrule arrangement surrounding the first fiber end section. The inner ferrule arrangement includes 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 sections has 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: A photonic crystal fiber (PCF) assembly including a PCF and at least one ferrule structure. The PCF includes a core region and a cladding region and a first fiber end section with a first fiber end. The ferrule structure is mounted to the first fiber end section. The ferrule structure includes an inner ferrule arrangement and an outer ferrule arrangement surrounding the first fiber end section. The inner ferrule arrangement includes 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 sections has 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: A hollow core photonic crystal fiber (PCF) including an outer cladding region and seven 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.

Abstract: A photonic crystal fiber (PCF) assembly including a PCF and at least one ferrule structure. The PCF includes a core region and a cladding region and a first fiber end section with a first fiber end. The ferrule structure is mounted to the first fiber end section. The ferrule structure includes an inner ferrule arrangement and an outer ferrule arrangement surrounding the first fiber end section. The inner ferrule arrangement includes 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 sections has 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: A hollow core photonic crystal fiber (PCF) including an outer cladding region and seven 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.

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: 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: 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 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.