Beam expanders and collimators are used to shape and condition the laser beam at the beginning of a free-space beam delivery system. They are typically the first optical component after the laser output and serve to either collimate a diverging beam or expand a collimated beam to the desired diameter and divergence.

We offer a couple different types of beam expanders/collimators, each with different features and purposes. 

• Fiber Lasers
  Select a model with a built-in fiber adapter (typically QBH or QD style). These units are available in collimating or expanding configurations, depending on your desired output diameter.

• Free-Space Lasers (CO₂, diode, etc.)
  Choose a system without a fiber input. These are typically installed downstream of another optic, such as a collimator or focusing lens.

• Available in 19 mm, 25 mm, 30 mm, 38 mm, and 50 mm mechanical series
• Match the series to the rest of your beam delivery components (e.g., tubes, mounts, benders)

• Collimators are designed to take a divergent beam and produce a collimated output of a fixed diameter (based on fiber NA)

• Expanders increase beam size and reduce divergence. Common fixed expansion ratios include 2X, 3X, and 5X

• Choose based on:

  • The size of the collimated beam you need

  • The required Rayleigh range or focus spot size

  • The aperture size of downstream optics

• Fixed expanders offer stable, pre-set output with no moving parts
• Adjustable expanders allow tuning of divergence and beam diameter via a rotating lens group
  These are ideal for field setups or systems requiring flexibility

• Most models are passively cooled and handle standard industrial laser powers

• Water-cooled options are available for high-power systems, especially in the 50 mm series

• Make sure the optical surfaces are rated for your average and peak power levels

Secure the expander or collimator to a stable base using the appropriate mounting collar or adapter.
Use dowel pins if repeatability is important.

If you're using a fiber-coupled model, insert the fiber connector (QBH, QD, etc.) into the rear port and tighten the locking nut.
Be sure the connector is fully seated and aligned — improper coupling can lead to poor beam quality or damage.

Use a visible or low-power beam to align the output with the rest of the beam path.
Make sure the beam is centered and travels cleanly through all downstream components.

Rotate the adjustment ring to fine-tune the output beam diameter and divergence.
Monitor the beam shape or focus spot to dial in optimal performance.

Make sure the expanded beam fits through all apertures downstream and doesn’t clip on any mechanical edges.

Once aligned, lock down the mounts and fiber connections.
Recheck alignment after powering on the laser at full power.

• Bigger isn’t always better.
  Don’t automatically choose the highest expansion ratio — larger beams can cause clipping or require bigger (and more expensive) downstream optics.
• Match your expander to your isolator or process head.
  Always check that the expanded beam fits cleanly within the clear aperture of the next component in the system.
• Adjustable expanders are great for R&D or field use.
  If you're experimenting with setups or tuning focus distances, an adjustable model saves time and avoids swapping hardware.
• Use the right fiber adapter.
  A mismatched fiber connector (e.g., QD in a QBH port) can lead to poor coupling or damage. Make sure the part number includes the correct adapter.
• Consider divergence, not just diameter.
  Expansion reduces divergence, which can significantly improve focusability — especially over long distances.
• Plan your beam height early.
  These components set the beam height for the whole system. Choose mounts and risers accordingly.
• Leave room for adjustment.
  Don’t box the expander in too tightly — you may need to rotate or tweak it during alignment.