Patent ID: 7400795

Claim:
An elongated light-guiding element having opposed incident and emission ends between which light is transmitted by internal reflection, the light-guiding element comprising: an optical glass core having longitudinally opposed first and second glass-core ends and a glass-core outer surface extending longitudinally between the first and second glass-core ends, the glass core being optically transmissive and exhibiting a glass-core refractive index; and an optical layer extending over a predetermined portion of the length of the glass core and being disposed peripherally about the outer surface of the glass core as viewed into a plane orthogonal to a longitudinal axis of the glass core, the optical layer having first and second optical-layer ends and an optical-layer exterior surface extending between the first and second optical layer ends; wherein (i) the first glass-core end coincides with the incident end of the light-guiding element and (ii) the optical layer is formed from a first non-glass polymeric material having an optical-layer refractive index corresponding as closely as practicable to the glass-core refractive index such that (a) the glass core and optical layer combine to form a light-guiding element that behaves as similarly as practicable to light-guiding element fabricated from a single, continuous mass of optical material having a refractive index equal to the glass-core refractive index and (b) when the optical layer of the light-guiding element is surrounded by a material having a refractive index lower than the optical-layer refractive index, light received into an incident end of the light-guiding element is transmitted through a portion of the length of the light-guiding element including a portion of the length of the glass-core and a portion of the length of the optical layer by internal reflection.