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?