Nonpolarizing cube beamsplitters consist of a pair of precision right-angle prisms that have been carefully cemented or mounted together to minimize wave front distortion. Nonpolarizing cube beamsplitters provide a true 50/50 split at a specific laser wavelength (e.g., 632.8), regardless of the incoming polarization. These beamsplitters are particularly useful with randomly polarized lasers and are specifically designed for applications in which polarization effects must be at a minimum.
Nonpolarizing cube beamsplitters are specifically designed to maintain the reflected and transmitted beam where the incident laser radiation polarization characteristics are applied. This occurs because these devices are less sensitive to polarization and because they are designed from (or are at least coated with) dielectric materials, which provide negligible absorption. The end result is stable performance regardless of the energy sources involved.
When determining which of the available nonpolarizing cube beamsplitters is best for a given application, there are three main specifications to consider that effect beamsplitter performance. These specifications are the transmission level of the device, the wavelength range produced by the nonpolarizing cube beamsplitter, and whether the device is coated. Transmission is the percent of incident light transmitted through the beamsplitter. As expected, the greater the percent of incident light available, the greater the concentration of output light. The wavelength range of the beamsplitter is simply the output range of the nonpolarized light (generally rated in nm). Some styles of nonpolarizing cube beamsplitters are available with antireflective coatings to increase transmission of light at the beamsplitter-air interface.