[robertlroberts]

I am attempting to set up a dual focus lens for laser cutting. I have a 5" fl final lens and a 1"fl first lens. The problem I have is when I install the 1"fl lens between the laser beam and the 5"fl final lens, I lose almost all the output power. The dual lens should reduce spot size and therefore concentrate cutting power. I have to be missing something.

[grawley]

The off-the-shelf focus lenses are designed to take in a collimated laser beam (that means the laser beam is coming straight into the lens). However, in your setup you angle the incoming side laser beam because you use an upstream focus lens.

There are a lot of geometric optic software programs that will show what is happening, and a lot of youtube tutorials on the subject, and you could simply sketch it out by hand after watching some informative youtube vidoes then see what is going on, then change your design or lens configuration. You can also contact suppliers of lenses for their assistance.

[cinematic2]

I am attempting to set up a dual focus lens for laser cutting. I have a 5" fl final lens and a 1"fl first lens. The problem I have is when I install the 1"fl lens between the laser beam and the 5"fl final lens, I lose almost all the output power. The dual lens should reduce spot size and therefore concentrate cutting power. I have to be missing something.

Dual focus lens do not means dual lens (flame2)