A polymer optical fibre (POF) (30) for transmitting light of wavelength, λi, between two separate elements of an active implantable medical device (AIMD), includes a core (31) which is cylindrical and made of a cyclic olefin polymer (COP) or copolymer (COC), having a core refractive index at the wavelength, λi, n_core, A cladding (32) which has a cladding refractive index at the wavelength, λi, n_clad<n_core, and which is made of a cladding copolymer including monomers of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride. The cladding being itself enclosed in a coating (33) which is made of a coating polymer formed of one of the monomers of the cladding copolymer. The POF has a numerical aperture, NA, at the wavelength, λi, of at least 0.5.

A polymer optical fibre (POF) (30) for transmitting light of wavelength, λi, between two separate elements of an active implantable medical device (AIMD), includes a core (31) which is cylindrical and made of a cyclic olefin polymer (COP) or copolymer (COC), having a core refractive index at the wavelength, λi, n_core, A cladding (32) which has a cladding refractive index at the wavelength, λi, n_clad<n_core, and which is made of a cladding copolymer including monomers of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride. The cladding being itself enclosed in a coating (33) which is made of a coating polymer formed of one of the monomers of the cladding copolymer. The POF has a numerical aperture, NA, at the wavelength, λi, of at least 0.5.

In some embodiments, a head-mounted augmented reality display system comprises one or more hybrid waveguides configured to display images by directing modulated light containing image information into the eyes of a viewer. Each hybrid waveguide is formed of two or more layers of different materials. The thicker of the layers is a highly optically transparent “core” layer, and the thinner layer comprises a pattern of protrusions and indentations to form, e.g., a diffractive optical element. The pattern may be formed by imprinting. The hybrid waveguide may include additional layers, e.g., forming a plurality of alternating core layers and thinner patterned layers. Multiple waveguides may be stacked to form an integrated eyepiece, with each waveguide configured to receive and output light of a different component color.

The material stack of the present disclosure can be used for fabricating optical waveguides that are thin and flexible, and that can bend light around small turns. The stack of materials can include a polymer core and a cladding, which together can create a large difference in refractive index. As a result, light can remain within the core even when bent around radii where standard glass fibers could fail.

An optical waveguide is provided and includes: a core forming layer with a high refractive index; and a first clad layer with a low refractive index, bonded to a first main surface of the core forming layer. The core forming layer is provided in its plane direction with a core portion, lateral clad portions each having one side adjacent to a corresponding side of the core portion, and high refractive index portions each adjacent to the other side of a corresponding one of the lateral clad portions. The core portion is provided in its plane direction with a central region, and GI regions in each of which a refractive index continuously decreases from the central region toward an interface with the corresponding one of the lateral clad portions. The lateral clad portions each include a region having a constant refractive index.

An optical waveguide is provided and includes: a core forming layer with a high refractive index; and a first clad layer with a low refractive index, bonded to a first main surface of the core forming layer. The core forming layer is provided in its plane direction with a core portion, lateral clad portions each having one side adjacent to a corresponding side of the core portion, and high refractive index portions each adjacent to the other side of a corresponding one of the lateral clad portions. The core portion is provided in its plane direction with a central region, and GI regions in each of which a refractive index continuously decreases from the central region toward an interface with the corresponding one of the lateral clad portions. The lateral clad portions each include a region having a constant refractive index.

A plastic optical fiber is excellent in translucency, heat resistance, resistance to environment and the like, and has highly excellent flexibility. The plastic optical fiber contains a core and at least one layer of cladding, wherein the bending elastic modulus of the innermost layer of the cladding is 20 to 70 MPa, the glass transition temperature of the innermost layer of the cladding is 10° C. or lower, and the storage elastic modulus of the innermost layer of the cladding at 30° C. is 1×10.sup.6 Pa to 4×10.sup.7 Pa.

A plastic optical fiber is excellent in translucency, heat resistance, resistance to environment and the like, and has highly excellent flexibility. The plastic optical fiber contains a core and at least one layer of cladding, wherein the bending elastic modulus of the innermost layer of the cladding is 20 to 70 MPa, the glass transition temperature of the innermost layer of the cladding is 10° C. or lower, and the storage elastic modulus of the innermost layer of the cladding at 30° C. is 1×10.sup.6 Pa to 4×10.sup.7 Pa.

An optical fiber is formed from silica glass, and includes a core, a first cladding which surrounds the core and has a refractive index lower than the refractive index of the core, and a second cladding which surrounds the first cladding and has a refractive index that is lower than the refractive index of the core and higher than the refractive index of the first cladding. The second cladding is divided into an inner region that is in contact with the first cladding and an outer region which surrounds the inner region and has a thickness that is half the thickness of the second cladding or less, while being 5 μm or more. The residual stress in at least a part of the outer region is a compressive stress.

A daylight redirecting window film formed by a flexible multi-layer film laminate with a total thickness of less than one millimeter and configured to be applied to an indoor-facing window surface of a building facade. The window film includes a pair of outer film substrates flanking a light redirecting core layer. The core layer includes a parallel array of channels defining total internal reflection (TIR) surfaces and linear optically transmissive structures protruding transversely thought the core layer and bonded to the outer film substrates. A light output surface of the outer film substrate which is disposed on an indoor-facing side of the laminate includes a two-dimensional pattern of light scattering microstructures which are configured to spread light at least in a plane that is perpendicular to the channels. The TIR surfaces intercept and reflect a portion of sunlight propagating through the core layer such that the window film redirects that portion of incident sunlight towards a plurality of divergent directions, forming relatively high bend angles.