Design and fabrication of trihedral corner-cube arrays using analog exposure based on phase masks

摘要

Trihedral corner cube arrays are efficient retro-reflectors. They are integral parts in numerous imaging andsensing applications. However, the fabrication of these trihedral arrays can prove to be both difficult andcost prohibitive. Using a phase-only mask, we have fabricated an array of analog reflectors which can thenbe tiled using a photolithographic stepper. The elements are designed using a fixed period and varying fillfactor to create the analog slope of each side wall. The overall depth of the array can be controlled by boththe exposure and etching processes to ultimately create the desired effect. After etching, a single coating ofmetal finishes the process, and the elements can then be diced out and integrated into each specificapplication. The etched arrays may alternatively be used as a mold to create high volumes of the desiredelement. The design and fabrication parameters for trihedral corner cube arrays will be discussed in detail.The advantages and limitations will then be discussed.