Cost-effective mass fabrication of multilevel diffractive optical elements by use of a single optical exposure with a gray-scale mask on high-energy beam-sensitive glass.

We present a method for reproducing diffractive optical elements in quantity. The method is compatible with VLSI microfabrication techniques and involves generating a gray-scale mask. The gray-scale mask is employed in an optical aligner to expose an analog photoresist on any environmentally durable substrate, e.g., glass, quartz, semiconductor, or metal, one exposure for each diffractive optical element. After copies of the mask on the photoresist are developed, many substrates can be processed in parallel in a chemically assisted ion-beam etcher to transfer the microstructures on the analog resists simultaneously onto the surfaces of the substrates.