New research in imaging may lead to advancements for the Air Force in data encryption and wide-area photography with high resolution. Researchers at Princeton University used a special optical device called a nonlinear crystal, rather than an ordinary lens, to capture an image. Every image is made up of a collection of light waves, and a lens bends (refracts) the waves towards a detector. In contrast, in the nonlinear material, these waves communicate to each other and interact, generating new waves and distorting themselves in the process. The mixing is a form of physical (vs. numerical) encryption, but it would be useless if the process could not be reversed. The proposed algorithm provides a way of undoing the image and thus recovering the original signal. If the signal itself is encrypted from the beginning, then this method would provide another layer of protection.
The reversing algorithm also allows the researchers to capture information that is lost in other imaging systems. Experimentally, the method relies on imaging both the intensity and travel direction of the waves. This is done by taking a standard photograph of the object alone and then one with the object and an added plane waves. The result, called a hologram, is then fed into the numerical code. The researchers obtained photos of various objects by using the image-capturing equipment, and in every instance, their images consistently have a wide view with a high resolution. They used an Air Force resolution chart, which is designed to check the quality of imaging systems. Imaging applications include optical systems that maintain their field of view as they zoom, sharper microscopes, improved lithography, and dynamical imaging of 3D objects.More information:
http://www.sciencedaily.com/releases/2009/07/090714165100.htm