An optical fiber includes: a first core portion capable of transmitting first light; a second core portion formed on an outer periphery of the first core portion in a structure different from that of the first core portion and capable of transmitting second light different from the first light. The second core portion is formed around the outer periphery of the first core portion, and a center of the second core portion is positioned in a region of the first core portion.

The present invention provides a polymer optical waveguide having a core, an under cladding and an over cladding, in which: the polymer optical waveguide has a first section on one end side in the light propagation direction where no portion of the over cladding exists and the core and the under cladding are exposed, and a second section on the other end side in the light propagation direction where the core is covered with the under cladding and the over cladding; and a relative refractive index difference among the core, the under cladding and the over cladding, a core width and core height in an end surface at the one end side of the first section, and a core width and core height in an end surface at the other end side of the second section satisfy predetermined relationships.

An optical network having at least one star coupler comprising transmit and receive optical mixers which are respectively optically coupled to transmitters and receivers of a plurality of optical-electrical media converters. Each optical-electrical media converter comprises a respective receiver optically coupled to the receive optical mixer by way of plastic optical fibers and a respective transmitter optically coupled to the transmit optical mixer by way of plastic optical fibers. The output plastic optical fibers attached to an output face of the receive optical mixer have a diameter less than the diameter of the input plastic optical fibers attached to an input face of the receive optical mixer.

A plastic optical fiber for a medical device lighting decreases the cost of a lens and simplify the design of a lighting apparatus, wherein the plastic optical fiber for a medical device includes a core composed of a (co)polymer containing methyl methacrylate as a main component and is characterized by including a cladding material composed of a copolymer having a fluorine weight composition ratio of 60 to 74%, and by having a theoretical numerical aperture, NA, of 0.48 to 0.65 and, thus, the plastic optical fiber has a high numerical aperture and also has excellent translucency and flexibility.

An optical fiber includes: a first core portion capable of transmitting first light; a second core portion formed on an outer periphery of the first core portion in a structure different from that of the first core portion and capable of transmitting second light different from the first light. The second core portion is formed around the outer periphery of the first core portion, and a center of the second core portion is positioned in a region of the first core portion.

Embodiments of the present disclosure relate to optical device fabrication using methods of discrete grating assembly and optical interconnection. Discrete gratings corresponding to one of an input coupling grating, an intermediate grating, or an output coupling grating of an optical device are formed on separated donor substrates. The donor substrates are diced into individual gratings and adhered to an optical device substrate. An inkjet material is disposed between the gratings to optically interconnect the portions of the optical device.

A polarization-independent orbital angular momentum modulator based on a chiral fiber grating, a method for manufacturing the same, and an orbital angular momentum beam generator. The orbital angular momentum modulator includes an optical fiber body having a spiral fiber structure, and the spiral fiber structure has a long-period optical fiber grating effect. The optical fiber body has a periodic spiral refractive index modulation in an axial direction. A period of the spiral refractive index modulation has a magnitude of hundreds of microns, and the spiral refractive index modulation is distributed in an axial direction, a radial direction, and an angular direction of the optical fiber body, and configured to excite a spiral phase to generate an orbital angular momentum beam

A multi-core optical fibre comprises a plurality of cores embedded in cladding. The cladding comprises a polymer. The cladding has an outer cross-sectional shape with an order of rotational symmetry of less than or equal to 4. By limiting the rotational symmetry of the multi-core optical fibre, rotational alignment of the cores with light sources/light detectors may be made easier. Also provided are optical cables and kits including the multi-core optical fibre, and a method of fabricating a multi-core polymer optical fibre.

A method of fabricating a multi-core polymer optical fibre comprises arranging optical fibre preforms in a stack, the optical fibre preforms each comprising a polymer core and polymer cladding surrounding the polymer core; and drawing and bonding the stack to form the multi-core polymer optical fibre. Any contaminants or impurities which collect on outer surfaces of the preforms may be confined to boundaries between the preforms, which may avoid attenuation of signals passed through the cores while at the same time reducing crosstalk between cores of the final manufactured fibre. Also provided is a multi-core polymer optical fibre obtainable by the method.

A method of fabricating a graded-index polymer optical fibre comprises preparing a cladding composition, the cladding composition comprising either a mixture of a cladding polymer and a dopant or a mixture of a cladding polymer precursor and a dopant; forming cladding from the cladding composition around a core, the core comprising a core polymer; and causing diffusion of the dopant into the core such that the dopant has a continuous concentration gradient, according to which concentration gradient the concentration of the dopant increases with radial distance from a centre of the core. The dopant is a compound having a refractive index which is lower than a refractive index of the core polymer. By distributing the dopant such that the dopant concentration is lowest at the centre of the core, the optical attenuation of the graded-index polymer optical fibre may be reduced. Also provided is a graded-index polymer optical fibre obtainable by the method.