RE: [Homebrew_PCBs] RE: 10W ~380nm UV LED for exposing Riston & other negative film photoresists
2013-11-18 by Boman33
Interesting thought: If the laser focal point is not needed to very short, the required mirror curvature is very slight. It would be easy to bend a plastic front surface mirror, maybe even a thin glass one.
It is easier to bend it into a convex shape so the narrow laser beam section could be expanded to match the wide section and then focused normally.
To get a as clean beam as possible I have done the opposite to the beam expander:
Using microscope objectives, the beam is focused on a very small pin hole. Any secondary beams or distortions does not get through the pin hole. The beam is collimated afterwards with a matching second objective.
High rigidity mounting and accurate alignment is required.
Bertho
From: Cristian Sent: Monday, November 18, 2013 08:05
At 12:11 PM 18-11-13, you wrote:
>Expander-round aperture-focusing is the easy way for an amateur.
>
>I do not think you want to use an aperture to get a round beam since
>it will waste power.
> As you suggested, cylindrical lenses will allow you to selectivelyCurved mirror will do the job, but I think is hard to find.
> focus X & Y independently.
>
>Mirrors curved in one plane will also work.
>
>Bertho
If you know a cheap 'one piece' producer, let me know, please.
I'd like to round-up a red laser.
Cristian