These measures include precise matching of prism pair wedge angles (to < 0.5 arcsec) and bulk material indices of refraction, as well as careful control of internal coating layer stresses to guarantee that the coating deposition process does not degrade transmitted wavefront performance (specified at < λ/10 at 632.8 nm). REO Risley prism pairs also feature low scatter, low loss surfaces with 10-5 surface quality to maximize throughput and laser damage threshold. REO can fabricate Risley prism pairs from a number of different materials suitable for operation at wavelengths throughout the ultraviolet, visible or infrared spectral ranges. Typical examples include fused silica, optical glasses, CaF2, ZnS, ZnSe, Ge and Si. Prisms of up to 150 mm in diameter can be produced, depending upon material. REO can also design and manufacture optomechanical beam steering subassemblies that maintain the full, inherent precision of these prism pairs.
High Performance Risley Prism Pairs for Laser Beam Steering
REO now offers a comprehensive family of matched Risley (wedge) prism pairs to enable high accuracy laser beam steering in a wide variety of demanding military, industrial and instrumentation applications. Beam steering accuracy with these coated optics is particularly dependent upon close matching of the prisms in a pair, and REO takes several steps to ensure this.