1550nm laser beam expander is a precision optical component designed for the eye-safe infrared band, widely used in LiDAR, fiber optic communications, remote sensing, and medical laser applications. The 1550nm wavelength offers an excellent combination of atmospheric penetration and high eye-safety threshold, making it ideal for long-range ranging and free-space optical communication.

Optical Design

These beam expanders utilize Galilean or Keplerian optical configurations. The Galilean design, consisting of a concave lens and a convex lens, offers compact construction with short overall length. The Keplerian design creates a real focal point between the two lenses, allowing the integration of a pinhole aperture for spatial filtering to enhance laser beam quality. High-quality fused silica material ensures excellent thermal stability and damage resistance.

Key Performance

Optimized for the 1550±10nm band with anti-reflection coatings, these expanders achieve transmission ≥96% typical, with transmitted wavefront distortion ≤λ/4. Magnification ratios range from 2X to 25X, with maximum output apertures up to 100mm or even 150mm. Select high-end models feature diffraction-limited designs, maintaining excellent wavefront quality in high-power applications.

Typical Applications

1550nm beam expanders are widely used in automotive LiDAR, atmospheric environmental monitoring, free-space optical communications (FSO), fiber optic sensing systems, defense ranging, and medical laser equipment. The unique eye-safe characteristic makes them particularly suitable for public-environment laser applications.