A fiber structural body includes a first fiber, and a second fiber spliced to the first fiber such that light having propagated through the first fiber propagates through the second fiber. At least one of the fibers is a photonic crystal fiber. The second fiber is coated with a first coating layer and a second coating layer in order from a splice surface, and the first coating layer has a refractive index n.sub.1 larger than that of a clad layer of the second fiber. In the fiber structural body, L, r, n.sub.1, and NA satisfy a particular relationship.

A waveguide with a hollow core (16) delimited by a closed contour includes a succession of arcs (20) of negative curvature, each arc including a chord (24), characterized in that the contour of the hollow core (16) includes small arcs (PA) and large arcs (GA) arranged alternately, each arc (20) being symmetric with respect to a straight line passing through the center (18) of the hollow core (16) and the middle of the chord (24) thereof, the ratio b=2Ra/C of the large arcs being greater than 0.9 for the large arcs (GA), Ra corresponding to the maximum distance between the chord (24) and the arc (20), C corresponding to the length of the chord (24).

Microstructured multicore optical fibre with a microstructure area, in which, at least two basic cells are embedded, where each of them contains a core, preferably made of glass, specifically including doped silica glass or polymer, together with the surrounding it longitudinal areas with lower refraction index vs. that of the cladding, which areas may adopt the shape of holes, filled with gas, in particular with the air or a fluid or a polymer or spaces of another glass with doping allowing to reduce refractive index (further referred to as holes), embedded in a matrix of glass, in particular of silica glass or polymer. The refraction index of the holes is decreased vs. that of the matrix of glass, in particular of silica glass or polymer. The basic cell is characterised by the diameter of D2 core, the diameter of D3 core and the distance between adjacent holes, corresponding to lattice constant A. The centres of the holes are localised on the vertices and the middle points of the sides of the hexagon, the centre of which is designated by the core; the length of side c of the hexagon, created by the centres of holes, is equal to the preferably doubled lattice constant A. The juxtaposed, at least, two basic cells are surrounded by the cladding, preferably made of glass, in particular of silica glass or polymer. A Device for addressing cores of the multicore optical fibre a fabrication method of the device for addressing cores is also disclosed.

An optical fiber device may include a core including a primary section and a secondary section. The secondary section may include at least one insert element inserted within the primary section at an off-center location with respect to a center of the primary section. The secondary section may twist about an axis of the optical fiber device along a length of the optical fiber device. A rate of twist at which the secondary section twists about the axis may increase from a first end of the optical fiber device toward a second end of the optical fiber device. The secondary section being twisted about the axis may cause an optical beam, launched at the first end of the optical fiber device, to be at least partially converted to a rotary optical beam at the second end of the optical fiber device.

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.

An optical waveguide includes a core region extending substantially along a lengthwise centerline of the optical waveguide, a first cladding region formed along a first side of the core region, and a second cladding region formed along a second side of the core region. The optical waveguide includes a first diode segment and a second diode segment that each include respective portions of the core region, the first cladding region, and the second cladding region. The second diode segment is contiguous with the first diode segment. The first diode segment forms a first diode across the optical waveguide such that a first intrinsic electric field extends across the first diode segment in a first direction, and the second diode segment forms a second diode across the optical waveguide such that a second intrinsic electric field extends across the second diode segment in a second direction opposite the first direction.

Structures with waveguide cores in multiple levels and methods of fabricating a structure that includes waveguide cores in multiple levels. The structure includes a first waveguide core and a second waveguide core positioned in a different level than the first waveguide core. The first waveguide core includes a longitudinal axis and a plurality of segments having a spaced arrangement along the longitudinal axis. The second waveguide core is aligned to extend across the plurality of segments of the first waveguide core.

The present invention relates to an optical fiber (100, 200, 300, 400) comprising one or more cores (102), a clad enveloping the one or more cores and a buffer clad layer (202, 302, 402) between the first clad layer and the second clad layer. Particularly, the clad includes a first clad layer (104) is made of silica with less than 0.1% metallic impurity and a second clad layer (106) is made of silica with greater than 0.1% of metallic impurity. Further, the first clad layer has less than 800 ppm OH content, less than 10 ppm aluminium and less than 2 ppm sodium and the second clad layer has less than 50 ppm OH content, more than 10 ppm aluminium and more than 2 ppm sodium.

A supercontinuum source including a pump source and a supercontinuum generator configured for receiving electromagnetic radiation derived from the pump source and for generating supercontinuum radiation, the supercontinuum generator including a nonlinear microstructured optical fibre having a core region comprising silica. The core region includes a dopant selected to reduce light-induced non-bridging oxygen hole centre loss in the nonlinear microstructured optical fibre.

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.