Using lenses, tiny lasers, and tunable light detectors, researchers at the University of Michigan's College of Engineering are designing an artificial eye on a microchip. Two approaches are being considered for the Army-funded research project. Both capture light with a variable focus lens array and shuttle it to a computer to process the data. The difference is in what happens in between. To preserve color, the lens system could be followed by a set of microprisms, which will defract the incoming light into three discrete bands -- red, blue, and yellow. Those beams in turn will pass into an array of photoreceivers that generate electrical signals, which in turn generate light beams at the individual wavelengths through a vertical cavity surface emitting laser (VCSEL). In the other approach, the device could skip the prism step and simply employ specially tuned photoreceivers with a VCSEL that creates the three desired colors. The designs converge again when the lasers strike the processing unit, the researchers add. Unlike the human eye, the device will be able to convert any wavelength of light into usable information. Nonmilitary applications could include vehicular navigation systems, robotics, and people with visual impairment, researchers say. The research team is led by Pallab Bhattacharya, director of the Solid State Electronics Laboratory.