| 摘要 |
<P>PROBLEM TO BE SOLVED: To permit focusing of a beam at a large solid angle in a luminous tube, and prevent the incidence of a high-energy-density beam on the wall of the luminous tube. <P>SOLUTION: The luminous tube 1 has a projecting meniscus structure and functions as a focusing means 31. A laser beam emitted from a laser oscillation unit 2 is focused by the focusing means 31 such that a solid angle will be increased in the luminous tube 1. This forms a high-temperature plasma state, causing the luminous tube to emit light. The wall of the luminous tube 1 functions by itself as the focusing means, thus to increase the solid angle during focusing, to prevent the irradiation of the beam focused onto the wall of the luminous tube 1, and also to prevent the luminous tube from being heated and broken. Other items may be used for the focusing means, as far as they are shaped to focus light, such as a convex lens or a rod lens. A plurality of light focusing means may also be provided. A similar effect is also achieved by installing the focusing means on the inner surface of the luminous tube. <P>COPYRIGHT: (C)2011,JPO&INPIT |
