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LED collimation using high-index glass

LEDs emit light over a broad range of angles. Additionally, a narrow collimation of LED light is difficult because of the broad emission area of the LED. In order to implement an efficient beam shaping with small optics we propose to use a glass lens design with a refractive index (nd) greater than 1.7. Our design is characterized by a very small size and a high efficiency. This enables us to design optical arrays with an extremely high packing density of LEDs. Additional advantages are the high temperature resistance, the climate resistance and the stability against solarization. For many applications the footprint of the light beam should not only be collimated but also formed into a specific shape. Design results for a rectangular or oval beam shaping using high refractive index glass are presented. The designs collimate the broad emitted LED light and are optimized to incorporate also the manufacturability of the lens. Our proposed lens designs can easily be manufactured by modern pressing techniques, thus, these solutions are suitable for mass production.