title: Laser direct-write gray-level mask and one-step etching for diffractive microlens fabrication.
abstract: High-efficiency diffractive optical elements can be achieved by an increase in the number of phase levels. We present a technique for laser direct-write gray-level masks on high-energy-beam-sensitive glass and one-step etching on the gray-level mask plate for the production of high-efficiency diffractive optical elements. Sixteen-phase-level diffractive microlenses and microlens arrays with a focusing efficiency of approximately 94% have been realized by use of the one-step nonphotolithographic fabrication technique.
authors.forename: M R
authors.initials: MR
authors.lastname: Wang
authors.forename: H
authors.initials: H
authors.lastname: Su