Abstract

Diffractive optical elements (DOEs) provide solutions for applications that require complex phase profiles which are difficult or impossible to make with conventional optics. Because of their planar nature, they have small volume and are light-weight, both of which are attractive features for many applications. Diffractive optical elements are typically fabricated by multi-mask-level photoresist patterning and sequential reactive-ion etching to form the multilevel phase profile^1,2. Other fabrication techniques include direct E-beam writing, direct laser writing, single-point ablation by excimer laser³, and thin film deposition. Here we describe a new technique for rapid fabrication of diffractive optic elements and arrays using deep-UV excimer laser ablation. We have fabricated 8-level diffractive micro-lenses which have diffraction-limited focusing and near-theoretical diffraction efficiency. This technique provides a flexible means for rapid prototyping and for applications where other techniques cannot be applied or are not cost-effective.

© 1996 Optical Society of America