Beam Expander

The most common type of beam expander is derived from the Galilean telescope which usually has one negative input lens and one positive output lens. The input lens presents a virtual beam focus at the output. For low expansion ratios (1.3-20 times) the Galilean telescope is most often employed due to its simplicity, small package size and low cost. * Material: BK7 fine annealed * Diameter: -0.1mm * Thickness: ±0.1mm * Flatness: l/4 * Surface Quality: 60-40 scratch-dig * Coating: HR dielectric coatingsR > 99%