Fabrication of plastic microlens array for array microscopy by three-dimensional diamond micromilling.

Two lens arrays of 20 lenses (4×5) are fabricated in polystyrene (Rexolite 1422) using a 3-D, three-axis micromilling process. The lenses of one array are concave (R(curv) = -2 mm) and the lenses of the other array are convex (R(curv) = 2 mm). A method for correcting a 3-D micromilling program for a single lens is described and evaluated. The lens separation is 4 mm and Ø(diam) = 2.6 mm for all lenses. Based on a measurement of key optical parameters (radius error, wavefront error, and surface roughness), micromilled lenses are shown to be of high optical quality compared with the form error and surface roughness obtained with plastic injection molded lenses.