Mastering Laser Beam Expander Optics with Scanner Optics

A laser beam expander lens is an optical device essential for enhancing laser processing systems. At Scanner Optics, our laser beam expander precisely adjusts both beam diameter and divergence angle, enabling focused, high-resolution laser applications such as marking, engraving, welding, and cutting.

What Is a Laser Beam Expander?

A beam expander functions like a reverse telescope, expanding the width of a collimated laser beam while maintaining parallel rays.

Keplerian beam expanders use two positive lenses separated by the sum of their focal lengths. They produce high magnification and allow spatial filtering via a focus point between lenses but tend to be bulkier and may not suit high-power applications. [1]

Galilean beam expanders pair a convex and concave lens, offering a compact design without internal focal points, ideal for CO₂ laser beam expanders and high-power systems, minimizing heat-related damage. [2]

How Beam Expanders Enhance Laser Performance?

By expanding the beam diameter, beam expanders reduce divergence, enabling a tighter focal spot when paired with an F-Theta or other focusing lens, crucial for precision in laser marking, micromachining, and ophthalmic imaging. [3]

Adaptive Laser Beam Expander Design

Fixed expanders maintain a constant magnification, such as 2×, 4×.

Zoom beam expanders allow adjustable magnification, typically ranging from 1× to 6×, enabling flexible spot size tuning for R&D or multi-purpose systems. [4]

Mitigating Aberration & Thermal Stress

Advanced beam expander optics designs consider optical aberrations like spherical distortion and use achromatic or air-spaced lens assemblies to preserve beam quality, even at high power levels, vital for CO₂ lasers.

Scanner Optics’ Laser Beam Expander Features

The laser expander lens from Scanner Optics ensure uniform beam profile and minimal distortion, offering both zoom and fixed designs with magnification ranges from 1× to 6×.

Our expanders are compact, lightweight, and easy to integrate, especially alongside F-Theta lenses for improved focus, with rugged build quality suitable for rigorous industrial environments.

We offer a range of models tailored to different laser wavelengths and applications, like fiber and CO₂ laser beam expander, with detailed specifications like input/output apertures and thread or clamp mounting options.

For custom configurations tailored to your system, such as specific expansion ratios, coatings, or compact form factors, reach out to Scanner Optics and optimize your beam delivery for peak performance.

Laser Beam Expander Applications Across Industries

The beam expanders enhance performance across diverse laser systems:

• Laser Marking & Engraving: Achieve finer resolution and marking precision.

• Micromachining & Cutting: Sharper focus improves speed and repeatability.

• Medical & Ophthalmic Devices: Enhances safety and control in sensitive procedures.

• High-Power CO₂ Processing: Galilean expanders help manage heat and intensity.

All these applications leverage divergence beam expander techniques to maintain beam control over distance and focus quality.

FAQs of Laser Beam Expander

What Types of Beam Expanders are Available?

• Galilean Expanders: Use a convex and concave lens, compact, and ideal for high-power lasers due to no internal focal point that could cause heat buildup.

• Keplerian Expanders: Use two positive lenses, allow higher magnification, and can include spatial filters. However, they create a central convergence point, which may cause heat issues with high-power lasers.

Can Beam Expanders be Adjustable?

Yes. There are zoom beam expanders that allow variable magnification, typically ranging from 1× to 6×. These are especially useful in prototyping or multi-purpose systems.

Can a Beam Expander be Used in Reverse?

Yes, but with caveats. A beam expander can act as a beam reducer when reversed, narrowing the beam diameter—but at the cost of increased divergence and potential internal reflections or damage if not specifically designed for reverse use.

What Design Factors Should I Consider?

• Lens aperture: Must accommodate the expanded beam without clipping.

• Coatings: Anti-reflective coatings tailored to your laser’s wavelength enhance transmission and reduce losses.

• Thermal handling: For high-power beams, use low-absorption optics and consider heat management methods.

Reference:

[1] https://www.shanghai-optics.com/about-us/resources/technical-articles/laser-beam-expanders-insights-and-applications/

[2] https://avantierinc.com/solutions/optical-lens-assembly/a-guide-to-laser-beam-expanders/

[3] https://precisionlaserscanning.com/2016/09/use-a-zoom-beam-expander-for-evaluating-an-f-theta-lens/