| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a visible light source having high conversion efficiency.SOLUTION: The vicinity of a filament 1 made of tungsten (W) is covered with a transparent silica tube with respect to visible light and infrared light, the outer surface of the silica tube 2 is covered with a high refractive index layer 3 having a refractive index nwhich is larger than the refractive index nof the silica tube 2, and the outer surface of the high refractive index layer 3 is covered with infrared light reflective multilayer 4. The infrared light reflective multilayer 4 transmits the visible light therethrough. At the end of the silica tube 2, a while scattering body (or a mirror) 5 is provided which totally reflects the visible light and the infrared light.</p> |
