科学美国人60秒:Go to the (White) Light

LEDs use only a quarter the energy of incandescent bulbs. But despite their efficiency, there is one thing they're not that good at: "They have a hard time giving directional light." Sangam Chatterjee, a physicist at the University of Marburg and the University of Giessen, in Germany.
LED灯使用的电量仅为白炽灯的1/4。但是尽管LED灯高效节能，但是它的一个缺点就是：不能发射平行光。Sangam Chatterjee是德国马尔堡和吉森大学的物理学家。

Chatterjee and his colleagues may have fixed that. They devised a highly focused, but still energy-efficient light beam, by starting with something that's already a highly focused beam: a laser. The key is what they shoot the laser at: a substance with a particular structure. "I'm always tempted to say "white powdery substance" but I guess there's some connotation on that."
Chatterjee和同事们修复了这个缺憾。他们通过高度聚焦的光束——激光，设计了高度集中、但是节能的光束。关键就是利用激光束射击一种有固定结构的物质。“我一直想说白色粉末的物质，但是其实关键的是内部的东西。”

They synthesized the material from cages of tin and sulfur atoms decorated with hydrocarbon molecules. The laser-produced infrared light—which the human eye cannot see—goes in, but what comes out are many different optical wavelengths. "It's a molecular light converter.
他们分析了材料的成分，烃分子修饰的锡和硫原子组成的结构。激光会发出红外线——肉眼看不到——射入，但是会产生很多不同的波长。“这种材料就成为了光转换器。”

It basically changes the color of the light, while retaining the directionality of the lasers. So you can make something like a white laser beam containing many, many colors." That mix of colors, overall, glows bright white, like a halogen bulb in a beam. The study is in the journal Science.
它基本上改变光的颜色，但同时保留激光的方向性。“白色光束包含多种颜色，你可以制作类似的光束。”混合的颜色就会发出像灯泡一样白色的光芒。该研究结果发表在《科学》杂志上。

This sort of low-energy focused white beam could be used for the very small—like a light source for microscopes—to the very big. "You could use this for a spotlight in the theater. And in the end it should be much more energy efficient than the typical standard spotlight that you have." Meaning focused white light…that takes a little heat off the environment.
这种低能的白光束用于放大——如显微镜的光源。“这种光可以用作剧院的聚光灯，比普通的标准聚光灯更加节能。”这意味着，聚着的白光可以消耗环境中的一部分能量。