LBTEK High-Precision Zoom Beam Expander supports continuous magnification adjustment within 1–4× / 2–10× range. When mounted in reverse, this variable beam expander can also function as a beam reducer. Fabricated with fused silica substrates, the optical components are coated with high damage threshold, low-absorption anti-reflection coatings, delivering stable and reliable performance under high average power or high peak power laser irradiation. Adopting a low-aberration, air-spaced sliding lens design, the variable beam expander is optimized to deliver near diffraction-limited performance while minimizing its impact on the M² value after beam expansion.