Abstract: An apparatus and method for generating a lamina of light. The apparatus includes an optically transparent member having an input configured to receive light and one or more facets formed in the optically transparent member. As light enters and travels through the member, a lamina of light is created by the light reflecting off the facets. In one application, the lamina of light is provided in the free space adjacent a touch screen display. When the lamina is interrupted during a data entry operation to the screen, an optical position detection device is used to determine the data input based on the location of the interrupt in the lamina. In various other embodiments, the position and uniformity of the lamina may be controlled by selecting the angle, depth and tilt of a reflective surface of the facets in the optically transparent member.