US Patent Issued to KLA on Oct. 14 for "Single-material waveplates for pupil polarization filtering" (California Inventors)

ALEXANDRIA, Va., Oct. 21 -- United States Patent no. 12,444,630, issued on Oct. 14, was assigned to KLA Corp. (Milpitas, Calif.).

"Single-material waveplates for pupil polarization filtering" was invented by Chong Shen (San Jose, Calif.), Guoheng Zhao (Palo Alto, Calif.) and Bret Whiteside (San Jose, Calif.).

According to the abstract* released by the U.S. Patent & Trademark Office: "An optical inspection system includes one or more single-material gratings to convert the polarization of light scattered from a target from an elliptical polarization that varies spatially across a collection pupil to a linear polarization that is uniformly oriented across the collection pupil. The one or more single-material gratings have phase retardation ...