Antireflective textured silicon optics at millimeter and submillimeter wavelengths

Silicon optics with broadband antireflective (AR) treatments are being developed for millimeter and submillimeter-wave applications. Combined photolithography and deep reactive ion etching (DRIE) techniques are used to texture the surfaces of high resistivity, low loss silicon wafers. We report on the design, fabrication, and testing at 250 GHz of single and double layer AR treatments on silicon optics.