High tensile strength optical waveguide - has two layer optical fibre with outer metal covering used for transmitting electrical signal

摘要

The waveguide has a glass core (11) having a first refractive index. It has a concentric glass covering (12) around the core. This has a refractive index lower than the value of the first. This second value is at least 0.1% lower in order to ensure total internal reflection of the radiations at the interface between core and conver. The waveguide has a malleable metal covering (13), over the outer glass layer (12), which provides the mechanical strength required of the waveguide, without hindering the optical properties. It may be used for simultaneous transmission of electric signals. A final plastic layer is extruded over the metal covering. The outer glass cover is 10-100 microns thick while the metal layer is 5-100 microns thick, making a total diameter of less than 300 microns.