EFFICIENT F 1 BINARY-OPTICS MICROLENSES IN FUSED-SILICA DESIGNED USING VECTOR DIFFRACTION THEORY/

The diffraction efficiencies of binary-optics lenses with low f/#'s de viate from predictions of scalar diffraction theory, To increase the d iffraction efficiencies for low f/#'s, vector diffraction theory is ne cessary. In this paper, we describe the design and fabrication of a 30 x 50 array of f/1 binary-optics microlenses using direct-write electr on-beam lithography and reactive-ion etching. The diameter of each len s is 160 mu m, and the focal length is 165 mu m. The center-to-center spacing between the lenses is 300 mu m, and they are fabricated in fus ed silica. The measured diffraction efficiency for an elliptical Gauss ian beam is 80% for lenses designed using vector diffraction theory an d 63% for lenses designed using scalar diffraction theory.