2. Optical sensors

Optical sensors can also be easily miniaturized using optical fibers. A fiber-optic bundle is made up of several thousand individual optical fibers (also called "cores"). Each core is surrounded by an optical cladding so that light is transmitted by total internal reflection. Their arrangement, ordered from one end of the bundle to the other, enables an image to be transmitted with micrometric resolution. Figure 3 shows the image of a bundle of 6,000 cores with a radius of 1.5 microns. The properties of such fiber-optic bundles have been exploited, for example by David R. Walt's group at Tufts University, to develop artificial noses and DNA biochips ( http://www.illumina.com...