Advances in high luminance LEDs for etendue-critical systems

The wide range of existing and upcoming optical illumination systems is supported by an equally large variety of LED solutions. Whereas some applications are bound by efficiency, efficacy, or space constraints, other systems are limited by etendue and luminance. Focusing on the latter group, we highlight the recent advances in high luminance chips and LEDs that enable state-of-the-art optical systems. In particular, we demonstrate three representative cases to benefit from high luminance. First, in flash LEDs for mobile devices, miniaturization drives the illumination system to the etendue limit. On top, increasing camera resolution requires more flux to maintain a reasonable signal-to-noise ratio. Second, concerning LEDs for projector systems, a fundamental challenge lies in generating sufficient green flux to feed through the imager etendue. Third, for LEDs in automotive exterior applications, high luminance enables smaller headlamp systems or alternatively high intensity spots.