Sub-100 nm manipulation of blue light over a large field of view using Si nanolens array

This study presents a super-resolution light manipulation technique in the near-field region of a silicon nanolens array in the blue spectral range using a computer-generated holography technique. It allows us to focus light into a spot below 70 nm at arbitrarily given positions within the entire lens array using modulated incident fields. To achieve this, an inverse design algorithm is developed using multiaxis high-order Gaussian beam expansion. It effectively corrects aberrations in off-axis focal spots within each nanolens unit, resulting in high-quality nanofocused beams with an extended depth of focus. By superimposing discrete nanofocused spots, we can further synthesize complex intensity patterns across multiple nanolens units, achieving an intensity profile resolution of 80 nm. This offers a promising approach for super-resolution photolithography using visible light.