Just some interesting science. http://www.physorg.com/news/2012-02-electron-detection-breakthrough-unleash- next-generation-technologies.html
"The researchers discovered that by shining light from a high-power laser onto a material that contains moving electrons, light of a different color is generated. They looked at thin crystals of gallium arsenide - a material commonly used in high-speed electronics and photonics. By applying a voltage across the crystal, they set electrons to move through it with a specified speed. By illuminating the crystal with an infrared laser pulse, invisible to human eyes, they found that visible red light was produced - a signature of the second-harmonic generation process. Additionally, they observed that the brightness of the red-light scales with the speed of electrons. When the electrons have no directional motion, no red light comes out. "By detecting the red light, one can accurately determine the speed of electrons without making any contact with the sample and without disturbing the electrons," Zhao said. -Mark
