M-Squared is arguably the most important factor when determining the potential efficiency of your laser.
But, it can be a pain to measure. Here are 2 ways you can use that actually DON’T move the camera or the laser
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:
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?
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.
A clear benefit of knowing the M2 of your laser is getting a lot of information about beam quality all in one number.
As simple as the output is, it is harder than you may imagine to measure and calculate M-Squared.
Let’s take a quick look at the theory behind M2 to see how it can be measured.