LBTEK's reflective beam expanders utilize two silver-coated spherical mirrors with a low-aberration design. After optimization, the system wavefront aberration is less than λ/10 (with an incident light diameter of 1 mm). They can expand (or reduce) the diameter of a parallel incident light beam to a fixed magnification. The beam expander's input and output ports have SM05 and SM30 threads, compatible with our SM-threaded lens tubes. They also feature four M3 tapped holes, compatible with our 30 mm coaxial systems. After the reflective beam expander reduces the polychromatic light, our reflective collimators can be used to couple the beam into an optical fiber. LBTEK also offers a variety of custom services, including customization of specific dimensions, operating wavelengths, beam expansion ratios, and other specifications. For specific customization requirements, please contact LBTEK technical support.