How to Increase Laser Welding Efficiency and Reduce Scrap

August 20, 2014

OphirBlog

Stop me when this sounds familiar.

Your laser welding system is not producing the quality welds you expected.

You know what your laser’s power density should be and where the laser should be focused, but you never know what it actually is, or where it’s really focused.

But measuring focus spot is easier said than done

It’s isn’t your fault, though. No beam profiler can measure such high power laser beams – at least not at the focus spot.

However, if you can’t measure your focus spot size and location, you may be doomed to scrap and slower production, not to mention all the time you’ll waste trying to get the perfect laser setup by trial and error.

The Solution: Measure focus spot size and location at any power

Luckily, there’s a new solution. Ophir-Spiricon’s BeamWatch measures focus spot size and location in real time. Better yet, there is no upper limit to the laser power that you can use with it. This unique solution measures Rayleigh scattering from the laser, without actually touching the laser beam at all.

BeamWatch focus spot size and position monitor

BeamWatch has two unparalleled advantages:

First, it measures your focus spot in real time (60 ms) so you can use it to diagnose the laser through its startup phase. Often the position of the laser focus spot shifts – especially during startup. Now you can actually see whether your focus spot location changes, and how much.

The other thing that makes BeamWatch so unique is the laser power it can handle. Since the laser beam passes through a hole in the BeamWatch body without actually touching the sensor at all, there is no upper power limit. Currently, BeamWatch has been tested successfully up to 100 kW. It is expected to work at higher powers just as well. (It does have a lower limit: BeamWatch is only intended for lasers of 1 kW power or more.)

Note: This solution is for YAG and fiber lasers with wavelengths from 980 to 1080 nm. So if you’re using a CO₂ laser I’m afraid this isn’t for you. Sorry.

Here’s what you get with BeamWatch

As you can see in the rough diagram below, you measure the distance between your laser’s output and BeamWatch, and BeamWatch calculates the precise location of the beam waist (or focus spot) of your laser. Use this value to position the laser so your focus spot will be at the best location with respect to your work piece.

BeamWatch laser focus spot size measurements

At the same time, BeamWatch measures the laser beam width at the focus spot as well. This will help you determine your maximum power density, which should be directly related to the effectiveness and speed of your process.

So here’s the question that separates the amateurs from the professional laser welders. Now that there is a solution, do you invest in your laser welding system, in your process, to make it as efficient and cost-effective as possible? Or do you keep on playing trial and error?

The choice is yours.

What’s it going to be?