Helmuth Ernst Meissner

Precision molded-glass optics

Results achieved in high-precision molding of glass lenses are reported. The work concentrated on a 0.4- N.A. 8-mm diam lens with spherical surfaces. The glass is a specialty glass composition of index (d-line) 1.604 and Abbe number 50. Typical design tolerances which have been achieved in the molded glass lenses include relative surface figure replication of 0.06 Aim, thickness and diameter tolerances of A+/-10 Am, wedge of <10-3 rad, birefringence of less than one one-hundredth wave, and index homogeneity in the sixth decimal place. These results are directly applicable to molding precision glass aspheric lenses of similar tolerances.