Branched hierarchical micro-truss structures may be incorporated into energy-absorbing structures to exhibit a tailored multi-stage buckling response to a range of different compressive loads. Branched hierarchical micro-truss structures may also be configured to function as vascular systems to deliver fluid for thermal load management or altering the aerodynamic properties of a vehicle or structure into which the branched hierarchical micro-truss structure is incorporated. The branched hierarchical micro-truss structure includes a first layer having a series of interconnected struts and a second layer having a series of struts branching outward from an end of each of the struts in the first layer.

Provided is an optical fiber cable having excellent flame retardancy, long-term heat resistance and mechanical characteristics. An optical fiber cable according to the present invention comprises an optical fiber and a cladding layer that is provided on the outer circumference of the optical fiber. The cladding layer contains a chlorinated polyolefin resin (A) and a polyolefin resin (B).

The present invention provides a plastic optical fiber comprising a core and a sheath consisting of at least one layer, the plastic optical fiber having a transmission loss of 120 dB/km or less as measured by a 25 m-1 m cutback method under conditions of a wavelength of 525 nm and an excitation of NA=0.45, and satisfying either one of the following conditions when a thickness of the innermost sheath layer is 0.5 μm to 4.5 μm, an amount of foreign matter having a size of 2 μm or greater contained in the innermost sheath layer is 2000/cm.sup.3 or less, or a size X (μm) of foreign matter contained in the innermost sheath layer and an amount Y of the foreign matter (number/cm.sup.3) satisfy formula (1) below: Y≦1200 X e.sup.(−0.067×X) (1). Such optical fibers have a low transmission loss of green light (in particular, light having a wavelength of 525 nm), enabling longer distance communication.

Technologies are generally described for fabricating a self-writing waveguide. Two photo-reactive liquid monomers, each infused with a photo-initiator, may be mixed and dissolved in a carrier solvent to form a mixture. Nanoparticles may be added to the mixture to form a gel. A focused light beam may be provided to cure one of the monomers, initiating polymerization to form a core of the self-writing waveguide. An optional exposure to an optical source, a heat source, or an electron beam source may cure the other monomer, initiating polymerization to form a cladding of the self-writing waveguide. The self-writing waveguide may be formed in a substantially tubular structure or a planar film structure.

Provided is a plastic optical fiber, which is suppressed from causing cracks even when used for a long period of time in a state of being subjected to an external force. A plastic optical fiber (10) of the present invention includes: a core portion (12); a cladding portion (14) arranged on an outer periphery of the core portion (12); and an over-cladding portion (16) arranged on an outer periphery of the cladding portion (14), wherein the over-cladding portion (16) has a birefringence Δn of 0.002 or more.

A method, includes providing a wafer including a first surface grating extending over a first area of a surface of the wafer and a second surface grating extending over a second area of the surface of the wafer; de-functionalizing a portion of the surface grating in at least one of the first surface grating area and the second surface grating area; and singulating an eyepiece from the wafer, the eyepiece including a portion of the first surface grating area and a portion of the second surface grating area. The first surface grating in the eyepiece corresponds to an input coupling grating for a head-mounted display and the second surface grating corresponds to a pupil expander grating for the head-mounted display.

A passive microscopic Fabry-Pérot Interferometer (FPI) sensor includes an optical fiber a three-dimensional microscopic optical structure formed on a cleaved tip of an optical fighter that reflects a light signal back through the optical fiber. The reflected light is altered by refractive index changes in the three-dimensional structure that is subject to at least one of: (i) thermal radiation; and (ii) volatile organic compounds.

Embodiments involve optical waveguides with spongy material for cladding or layers that include compressible gas pockets. The refractive index of the porous cladding material will change when compressed, bent, or stretched. Measurements for pressure, strain, bending, etc., may be obtained by monitoring the signal degradation and/or escape of radiant energy, e.g., IR, etc., from the core and out through the spongy cladding, where it may be picked up by a neighboring core. Optical waveguides configured as fibers may be easily sewn to stretchable materials, such as athletic tape, fabrics used in umbrellas, balloons, fabrics used in clothing, etc., to meet a robust number of applications.

A light-emitting fiber includes a core and a cladding and is configured to emit light through a side surface of the fiber. A resin used for the core is at least one selected from the group consisting of polymethyl methacrylate, polymethyl methacrylate copolymers, polystyrene, polycarbonates, polyorganosiloxanes, and norbornene, and a resin used for the cladding is fluorine resin. The light-emitting fiber has a fiber diameter of 95 μm or less.

A method is disclosed including causing a preform 1 that is softened to pass from an inner side of a container-shaped member 10 having a shape of a container having a through hole 12 at a bottom thereof through the through hole 12. The preform 1 includes a resin. At least an inner surface 10i of the container-shaped member 10 is formed of a material including glass, a heat-resistant resin, or aluminum as a main component. In one embodiment of the present invention, the preform 1 is heated while the preform 1 and a metallic member 20 in which the container-shaped member 10 is disposed are not in direct contact with each other, and the preform 1 softened thereby is caused to pass through the through hole 12 and then through a tubular portion 26 of the metallic member 20 to shape the preform 1 into a fibrous shape.