Profiling small laser beams and measuring the beam size (or mode field diameter) can be a serious challenge. But it’s critical to measure, especially in such applications as fiber optic coupling efficiency, defect scanning, optical design and optical fabrication process control. Here’s how we suggest you do it
I’ve mentioned BeamWatch before.
It’s an innovative technique for profiling high power lasers (1 kW and up).
I’ve even touched on the underlying Rayleigh scattering effect that makes this possible.
But how does this really work?
When focusing a laser, or anything for that matter, there’s a handy formula that is used to calculate the focus size and position.
It is generally called the thin lens formula, and it looks like this:
CCD camera beam profilers are very sensitive to light.
So what happens when we consider ambient light? How about other light sources in the area, such as laser pumps?
There are two issues that can be caused by unwanted light getting into the camera:
With all the advancements in laser technology, lasers have become higher quality and more consistent.
Laser manufacturers test and measure their lasers during development, to make sure you, the laser end user, get the highest quality laser system.
With all this in mind then, do you really have to measure your laser system?
What are the four things you need to know when selecting a laser beam profiling system? Learn from Ophir-Spiricon’s sales engineers – the experts in the field of measuring lasers – what you need to know to get the most out of your laser beam.
What’s M-Squared, again?
If you’re not familiar with M2 already, it basically sums up your laser beam quality in a single number.
M2 takes a look at your beam caustic (the curve of the laser beam as it focuses and diverges again) and compares this to an ideal Gaussian beam caustic.
So if your beam is perfectly Gaussian, you’ll get M2 = 1. For high quality beams, M2 might be 1.1 or 1.2, for lower qualities you can get up to 3, 4 and even double digits for some low quality high power lasers.
So, how do you know what the M2 of your laser beam really is?
Modern production facilities must constantly increase throughput, at less cost, with less scrap, and with minimum downtime. In this video overview, you will learn how application of new, advanced technology in measurement devices, can help both designers and users of industrial laser systems to optimize and control their processes, so they can accomplish these goals and achieve consistently good results – both in quality and quantity.
Lasers are made of matter – of stuff.
And anything made of matter will degrade with time.
So if the laser degradation and eventual failure is inevitable, what can be done?
Let’s be honest.
We’d all just prefer that our lasers always worked exactly as they’re supposed to.
Who really wants to measure their laser, when they can just be using it instead?
However, like all processes, a laser must be controlled to be used efficiently, and it must be measured to be controlled (and used) properly.
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