First lens before M1


Can anyone help me by explaining the purpose of the first lens before the first mirror I have highlighted in the picture below? I’m wondering if it is essential as I see some lasers don’t have it, and I was wondering if it’s purpose is just to reflect the guide light towards M1. If it is not essential can it interfere with the laser in anyway?

For reference I have a 60W CO2 Gweike Storm 600.


That looks like a red dot combiner.

Search for “combiner” and you’ll see quite a few posts about them.

Some people never use them, others can’t imagine doing without, as far as I can tell.

I can see a red glow on that combiner lens and behind it so surely there is a red laser element pointing at it somewhere… You can block that and verify the red dot at your laser head disappears when you cover the output of the red laser pointer element.