This image shows how the PSi square GRIN microlens focuses and splits TM- and TE-polarized light, respectively. TM-polarized light is focused at one point while TE-polarized light is focused at two different points. The refractive index gradient for the square microlens under the two different polarizations is illustrated using the color map overlaid on the lens (blue is low refractive index, orange is high refractive index). Image: University of Illinois.
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