Laser Scanner for 3d Printer Application

[Jimbo2032]

I have seen an application online in which a 405nm laser was able to successfully cure a 385nm resin, it was a resin from Bucktown Polymers.

I like the idea of driving the LD with a closed loop power supply, but from what I have seen few of the cheaper diodes out there have a PD in the can. Has anyone seen a project where they succesfully implemented an external PD? I would imagine that I would need to use a beam splitter to divert part of the beam into an external device (photo diode). In one thread on these forums someone mentioned that clear glass mounted at a 45* angle would do, but I would think that the losses would be tremendous, and there would be a fair amount of dangerous laser light being transmitted throughout the room due to the glass not being designed with optics in mind.

 

[Bionic-Badger]

External photodiodes are used all the time. Just add a piece of glass or a dichroic filter in front of the laser to reflect off part of the beam to the detector. If you buy one of those laser sleds, they should come with the necessary optics to do that, maybe even the photodiode itself.

 

[Marwin]

Jimbo32,

You should know that company named Formlabs is selling printers based on this idea. Here you may see photos of whats inside the printer Formlabs Form 1 Teardown « bunnie's blog
Assume these scanners were used 20KPPS Hightspeed Galvo Scanner for Laser Lighting New Without Show Card | eBay.
I am owner of the printer and here Episode 2 : Form1 calibration strikes back | An Idea per day we have a discussion about calibration issues.