Microlight-emitting diode with integrated Fresnel zone plate for contact lens embedded display (vol 11, 033010, 2012)

We report the fabrication and testing of 30-mu m radii circular InGaN blue light-emitting didode (LEDs) grown on sapphire wafers, with cointegrated Fresnel zone plates (FZP) with outermost ring radii of 99.6 mu m on the backside of the sapphire substrates to provide a collimated output. After being embedded on a contact lens platform such LEDs with integrated lenses can aid in producing in-focus images on the human retina. We measured an image width of 50 mu m created by a FZP f/3 subsidiary focal point at 230 mu m from the surface. We also demonstrate the construction and wireless operation of a contact lens with predetermined embedded text. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE).