| Introduction: | These D-shaped pickoff mirrors, which are available with a number of different coatings, are designed to enable the separation of closely spaced beams. D-shaped mirrors are ideal for picking off one of two closely spaced beams because the reflective coating extends to within 0.1 mm of the straight edge of the mirror. In addition, a wedge of the substrate is removed from behind the straight edge of the mirror in order to prevent the beam that was not picked off from clipping the pickoff mirror. |