Anamorphic lenses for laser diode circularization

摘要

Abstract: The design, fabrication, and testing of a new anamorphic microlens for laser diode circularization is presented. The microlens is fabricated using photolithography, gray scale masks, and reactive ion etching. A front-to-back mask aligner is used to precisely align two anamorphic aspheric microlenses on opposite sides of a single wafer, creating the ability to circularize or collimate a laser diode with only a single monolithic element. The entire fabrication process is highly nonlinear. This requires that accurate surface metrology methods be incorporated into the process as a feedback loop for iterative corrections to the gray scale mask. We discuss the measurement process and the effects of surface errors for circularizers and circularizer/collimators. This device has been under development for about two years at MEMS Optical. The most recent fabrication and test results of an actual device are presented. !3