High-energy polarizing cube beamsplitters provide efficient narrowband polarization for use with Nd:YAG lasers. Each polarizer consists of a pair of precision right-angle prisms optically contacted together. No cement is used. The hypotenuse of one of the prisms is coated with a multilayer dielectric polarizing beamsplitter coating optimized for wavelength at 248, 355, 405, 532, 1064, or 1550 nm. The lack of cement at the interface means that the laser damage threshold is maximized. The four faces are antireflection coated with a multilayer dielectric coating to minimize surface reflection losses.An unpolarized beam is split into two orthogonal, linearly polarized components. P-polarized light is transmitted, while s-polarized light is reflected, both with negligible absorption. The extinction ratio is better than 200:1. This unique component provides all the benefits of a thin film plate polarizer in a standard cube configuration.High-energy polarizing cube beamsplitters are available in 5.0, 10, 12.7, and 25.4 mm and can be conveniently mounted on Newport holders.