LBTEK Reflective Beam Expander utilizes two spherical mirrors with metallic coating, adopting a low-aberration design. After optimization, the system wavefront error is less than λ/10 within a specific input beam diameter, and it can expand (or reduce) the diameter of a collimated input beam by a fixed ratio. After the polychromatic light passes through the reflective beam expander to reduce the beam diameter, the beam can be coupled into an optical fiber using our reflective collimator. The input and output ports of the beam expander feature SM05, SM1, or SM30 threads, compatible with our standard SM series threaded lens tubes, and also include four coaxial mounting holes, compatible with 16 mm or 30 mm coaxial systems. LBTEK also offers various custom solutions, including custom dimensions, wavelength range, expansion ratio, and other specifications. For specific custom requirements, please contact LBTEK Technical Support.