Scanner mirrors for 405nm

[ZeroPoint]

I bought a budget pair of scanner mirrors a while back to replace the broken ones on a cheap 15kpps scanner set I have. I'm turning a Chinese box I have into a 405nm projector to do some work with glow in the dark paint. Unfortunately, after setting everything up I've discovered that my waste beams contain about 80% of my total power... It turns out these mirrors are coated for about 445nm and up. Where is the best place to look for galvo mirrors? They don't have to be top quality (in fact I'd prefer a more budget oriented pair since this is a cheap project) but they do have to work down to 400nm. Thanks for any suggestions.

[dazebtwn]

Check with Dave at LaserShowParts. Back in 2008 he sent me 6x11 mirrors that only had 10% loss at 405.

[mixedgas]

Overcoated silver will work at near UV and UV.

Steve

[ZeroPoint]

I looked at Dave's website but haven't messaged him personally. He doesn't advertise scanner mirrors but perhaps he has some lying around. So far I just purchased a small piece of aluminum coated front surface mirror to have a go at cutting my own. I'm sure silver would be better but the wavelength graph they provided seems to imply close to 85% reflectivity at 400nm so I'd be happy with that. Assuming I can cut the glass with no trouble I should get 4 sets of mirrors for $30. Guess I can't complain. I'll message Dave as well in case my own attempt goes south. Thanks for the replies.

[dkumpula]

I've built three glow in the dark projectors to date and found the stock mirrors on a set of Compact 506's and a set of old pt-40 pros to handle 405nm just fine. IR on the other hand resulted in 80%+ loss. To address that, I had Ryan at Pangolin swap out the stock mirrors for silver coated mirrors instead. This worked great and the difference in mirror price was around $25 if I recall correctly.

Cutting your own mirrors is going to leave you with jagged edges. You really need to coat after cutting and taking care of the edges. Bill Benner has a chapter in his new book that explains it if you are willing to spend the steep cost of the e-book. (Just kidding, the e-book is only $0.99!)

David

[ZeroPoint]

I'm pretty sure the old mirrors that came on the scanners worked just fine too since it was an RGV projector. I found a cheap pair of replacements on eBay and took a gamble. Interestingly enough, I just checked the post again after realizing how poor they reflect UV and the ad does claim its good for "all laser wavelengths". Such is Chinese advertising i guess. I did find another seller with what looks like identical mirrors but they actually list them as being for 445nm-670nm. I figured a decent set of stock mirrors would work fine (like the 506's or the DT/PT-40's) but I can't seem to find a source for replacement mirrors without having to PM or email someone. I was hoping to find a site thats stocks some so I could just place an order directly but veryone seems to only sell complete scanner sets. eBay has tons of scanner mirrors for cnc cutters and engravers but they are all too large. I'm surprised Stanwax Laser and Dave's Lasershow Parts don't stock anything. I couldn't even find anything from Goldenstar or Thorlabs, Edmund and Newport. I'm sure they are out there I'm just surprised how hard they are to find.

I definitely realize that cutting my own is less than ideal, however, this is just a cheap project that will have no professional use so I am less concerned with possible imperfections in the mirror and projection as I am with just passing at least 75% of the light. Plus, I'm a very impatient person so when I couldn't find a set to buy within the first 3 hours I felt I needed to just get something in the mail to at least experiment with, lol.

[dkumpula]

I probably have an old set of small mirrors sitting around somewhere that I could just post to you for free. Let me take a look and test with 405nm.

-David

[dkumpula]

Sadly, I just spent an hour digging through boxes and didn't find any spares. I'll keep my eyes open though.

[ZeroPoint]

thanks for the thought anyway

[-bart-]

I was thinking aboug building an uv projector too.
What diode(s) do you use and do you have thoughts about the hest lens to use?
Because many collimating lenses are coated for visual, which may result in high losses.