Very cool, this should make it easier to make better observations of spectra in gasses and other things.
Sanders’ laser builds on a phenomenon known as supercontinuum generation, in which researchers convert single-color lasers, such as a green or a red laser, into a multicolored beam using a special kind of optical fiber. Photonic crystal fibers enable them to generate this “white” laser beam, says Sanders.
While that method produces a range of laser colors-and thus, a large amount of information-the drawback is that the white laser delivers all of the colors simultaneously, says Sanders. Rather, researchers want to measure rapidly their subjects’ responses to individual colors.
So by directing the laser through an additional optical fiber about 20 kilometers long, Sanders created what he calls a “color-dependent speed limit.” Although all of colors leave the white laser at the same time, red travels through the fiber more quickly, while blue brings up the rear, and the rest of the colors fall somewhere in the middle. In photographs, they look like a continuous stream; in reality, each color exits the long fiber one after the other, like drops from a faucet. The entire laser scan occurs in a couple of millionths of a second.
Multicolor Wavelength-Agile Lasers At Your Service
