Abstract: In an optical waveguide comprising a transparent cladding (1) filled with a transparent liquid core (2) having a higher refractive index than the cladding, a liquid consisting of an oligomer having a phosphazene skeleton, typically phosphazene oil is used as the core (2). The waveguide is well resistant to heat and weathering, ensures stable performance in a wide temperature range over a long period of time, and provides good light transmission in a wide wavelength range covering the UV, visible and IR spectra.

Abstract: An optical waveguide hose includes a hollow tubular cladding, a fluid core in the cladding, the fluid having a higher index of refraction than the cladding, and sealing plugs mated with opposite end openings of the cladding. In one form, the core fluid is filled in the cladding under positive pressure. In another form, a sheath of a gas barrier material encloses the outer periphery of the cladding. The pressurized fluid core or the gas barrier sheath prevents air from penetrating into the core, allowing the hose to maintain its light transmission function.

Abstract: A pressure-sensitive sensor comprises an optical wave guide consisting of a core and a clad, and a light emitting means and a light receiving means each connected to the optical wave guide. The core is made from a transparent material having a refractive index somewhat larger than that of a material constituting the clad and selected from chloroprene rubber, urethane rubber, silicone rubber, fluorine rubber, acrylic rubber, ethylene-propylene rubber, ethylene-propylene-diene terpolymer rubber and epichlorohydrin rubber.

Abstract: A pressure-sensitive sensor comprises an optical wave guide consisting of a core and a clad, and a light emitting means and a light receiving means each connected to the optical wave guide. The core is made from a transparent material having a refractive index somewhat larger than that of a material constituting the clad and selected from chloroprene rubber, urethane rubber silicone rubber, fluorine rubber, acrylic rubber, ethylene-propylene rubber, ethylene-propylene-diene terpolymer rubber and epichlorohydrin rubber.

Abstract: A wave absorber comprising semiconductive ceramic short fibers having defined diameter, aspect ratio and volume resistivity dispersed in polymer materials. The dispersion is usually formed on a sheet or film base as a layer. A method for making the wave absorber is also described.