Beam expander is an optical component built to enlarge the diameter of collimated input beam and reduce the beam divergence. It's primarily applied in applications of Laser scanning, laser cutting, interferometry and remote sensing. A typical Galilean type beam expander consists of one negative lens and one positive lens. CASTECH provides the beam expanders of both adjustable divergence and non-adjustable divergence types. Our portfolio covers diverse variation of magnification and output diameter so that ideal for a wide range of demands of our customers. All the optics inside are well-polished and AR coated to exhibit high beam quality with low loss.