Nanometer- and Micrometer-scale LED arrays are useful not only for display applications, but also for specialized applications like lens-less microscopy, mask-less lithography or optogenetics. In these contexts, the spatial resolution of the optical field and precise control over the illumination pattern at the object plane is of special importance. We have studied numerically different GaN LED array designs, calculating light extraction, optical near field and crosstalk between pixels. We find that 3D-patterning can help in shaping the light emission, while optical crosstalk becomes a critical issue for small LEDs and pitches below 300 nm.
|