Dear,

I think that using a convex lens you can focus the laser beam on target to obtain high optical power. In this way, the target should be placed at focal depth. Also, the matching of light wavelength with lens is an issue. Please consider the following link to select an appropriate lens:

https://www.edmundoptics.com/c/laser-lenses/758/

Dear Tirimisiyu Olaniyan

You may firstly expand your laser beam with a telescope-type beam expender, so your output laser beam can be collimated before it reaches an off-axis parabolic mirror. Then your final laser beam focal spot can be varied by choosing the off-axis parabolic mirror with different focal lengths.

You may mount this parabolic mirror on an angular positioner so as to achieve accurate x-y adjustment of the laser beam spot on your workpiece.

Yours Sincerely

Dawei Liang

Dear Tirimisiyu Olaniyan

My previous answer was for a common laser beam with a slight beam divergence, but it is not adequate for focusing the highly divergent beam from a laser diode stack. In this case, a complex lens system is necessary, not only to focus your highly divergent laser beam into small spot, but also to correct the different laser beam divergences of the laser diode beam in X-Y directions, so that a final circularly symmetric spot can be achieved on your workpiece

Dawei

Dear Tirimisiyu,

please consider also technical issues like the protection of the optical system from dust and dirt. I do not know the work environmet exactly you are planning to work in (and the characteristics of the materials to use), but maybe think about protecting the optics (in case they are too close to a dust/dirt source) with some constant air flow. Otherwise, dirt will burn into the optics and destroy them. If you find this important, please consider also, that you should use clean and dry preassure air, not industial preassure air as air from standard systems contains oil and water.

Best regards,

Hermann

Thanks