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.
© 1998 Optical Society of America
(050.1950) Diffraction and gratings : Diffraction gratings
(050.1970) Diffraction and gratings : Diffractive optics
(080.3630) Geometric optics : Lenses
(220.4610) Optical design and fabrication : Optical fabrication
(350.3950) Other areas of optics : Micro-optics
Michael R. Wang and Heng Su, "Laser Direct-Write Gray-Level Mask and One-Step Etching for Diffractive Microlens Fabrication," Appl. Opt. 37, 7568-7576 (1998)