Fabrication of Customized Diffractive Optics in under 10 Minutes via Single-Shot Grayscale Projection on a Consumer-Grade DLP System

Fabrication of diffractive optical elements (DOEs) is typically slow, costly, and requires specialized expertise, motivating the need for a rapid and accessible alternative. Here, a maskless, cost-effective grayscale lithography approach is introduced for the rapid fabrication of DOEs. The method relies on the single-step projection of a grayscale pattern onto a droplet of UV-curable resin, followed by immersion-oil sealing under near-index-matching conditions. This process reduces the fabrication cycle from several days to about 10 min, remains user-friendly and reliable, and does not require specialized skills. A calibration procedure enables conversion of a phase map into a grayscale pattern without requiring precise direct measurements of the refractive index. The approach demonstrates the fabrication of a vortex plate, Zernike polynomial masks, and phase masks for 3D localization microscopy, all showing strong agreement with simulations. The technique does not require specialized facilities and can be implemented with desktop resin 3D printers, making custom DOE prototyping accessible to a wide range of researchers.