Abstract

We have proposed micro Fresnel lenses and their fabrication using a computer-controlled electron-beam writing system.¹ The lens has the following features: 1) Micro groove patterns can be written to real scale directly and precisely, and therefore the fabrication process is simpler than the case of photolithography. 2) Lenses of different specifications (focal length, wavelength, etc.) can be made only by modifying the computer programs. 3) Since each groove can be optimumly blazed, the diffraction efficiency can be high. Using the technique we have fabricated several kinds of circular and linear microlenses.

© 1984 Optical Society of America