A line of sapphire wave plates from Meller Optics Inc. can be custom-manufactured in a variety of sizes for use in visible and IR polarization control components. They provide λ/4 and λ/2 retardation with tolerances of >λ/300 at 0.62 µm, >λ/400 at 1.06 µm and >λ/1000 at 2.94 µm to change the polarization state of a laser beam from linear to circular and vice versa. Moh-9 hardness enables production of these wave plates as thin as 0.4 mm and <25 mm in diameter, with a transmitted wavefront of λ/10 at 632.8 nm. Suitable for use in high-power IR and VIS lasers, the low-order wave plates extend the wavelength beyond quartz to 4.7 µm and provide 0.25- to 4.7-µm transmission that is >98% with AR coatings on two sides. They achieve 10-5 scratch/dig surface quality and <2.0-arc-sec parallelism.