How To Measure A Large Laser Beam Profile

Laser beams tend to be very small when you want to look at the beam profile at their focal point or when they are collimated. It’s a challenge that we won’t cover here. What we will cover here is what to do when the beam doesn’t fit in your beam profiler sensor.

Typically, a beam profiling camera sensor is about 1 cm width or smaller. Some sensors can even go up to 20mm X 20mm, but beware that the price of the camera increases with its sensor dimension.

WORKING WITH A CAMERA LENS

What you can do if you want to measure a beam profile that is bigger than the beam profiler's sensor is to work with a camera lens. The sensor on the beam profiler is similar in size and behavior to one you’ll find in a reflex camera. Therefore, if you shoot a laser directly at it you will see the energy distribution of your laser.

If you install a camera lens in front of the sensor, such as our CL-25 camera lens, you will be able to aim the laser at a non-reflective surface and image its profile on the beam profiler. We must avoid a surface that will have a specular reflection such as a mirror. You need a surface that will have a diffuse Lambertian reflection.