PROVIDENCE, R.I., July 10, 2014 — Replacement CO2 laser beam delivery optics for etching stone featuring longer focal lengths are available from Laser Research Optics. The optics feature 4- to 7.5-in. focal lengths and are available in diameters from 0.75 to 1.5 in. They include zero phase-, phase lock-, rear mirrors, output couplers and phase retarders designed for lasers of 50 kW and greater power. Mirrors are made from single-crystal silicon and have an enhanced silver coating for 99.6% minimum reflectance at 10.6 µm.