Optical transmission tube, making method, and linear illuminant system

A method for preparing an optical transmission tube, comprising the steps of:

• dispersing scattering particles in a core-forming solution comprising a monomer capable of forming a core upon polymerization,
• filling a tubular cladding with the scattering particle-dispersed core-forming solution,
• resting the tubular cladding horizontally for allowing the scattering particles to settle on a lower inner surface of the cladding, and
• thereafter, causing the core-forming solution to polymerize and solidify within said cladding, thereby forming a solid core within said cladding and forming a reflecting layer composed of the scattering particles in a strip form extending between said cladding and said core and longitudinally of said cladding.

A linear illuminant system comprising

• a light transmission tube including a transparent core and a cladding having a lower index of refraction than the core, and serving as a light emergent element,
• a reflecting layer in a strip form extending between said cladding and said core and longitudinally of said cladding,
• a light source coupled to at least one end of said light transmission tube in a water-proof manner, and
• a drive means for operating the light source,
• wherein said light transmission tube is constructed such that when light emitted from the light source is transmitted by said light transmission tube, light emerges from a longitudinal side of said light transmission tube.