PLEASE DO NOT CHANGE THE OPTICS TO CONCENTRATE THE LIGHT.
Everything you said is true, and it would work IN THEORY. But we are dealing with a laser that has been
carefully constructed to be eye-safe. Changing the optics to concentrate the light could make it harmful.
You would need a laser-qualified engineer and be willing to retest your design and submit your findings to the FDA.
940nm light is invisible. It will also penetrate your eye. And you will not know to blink, or turn away.
So keeping the light dispersed so not very much can enter your eye is very important.
So without a fully qualified engineer, please do not change the optics.
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