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.