Cutting glass into tiny pieces to fit into lens barrel.

I've found IR-filtering glass without any issue (ebay, elsewhere) but all of it is either a large "bulk" piece, or is otherwise the wrong size. I would like to make a 6mm diameter circular piece to fit into the M9 lens barrel. All of the lens assemblies that I use are set up "backwards" i.e. the little retaining ring faces outward, so I could use a ~7mm glass piece as well.

The IR filter will be the final component in the lens assembly, and will also act as a window to keep dirt and contaminants away from the lens.

Any tools designed to efficiently cut/shape such small pieces of glass?

I'm thinking I could use a fine diamond file to slowly grind the glass piece down to size. I would use something like masking or painter's tape to cover the optical surfaces during this process, so as to protect the AR coatings and whatnot. Once the piece is a satisfactory fit, remove tape and clean with rubbing alcohol, and install.

Would that work? Is there some other tool I could go for that would allow me to reliably cut small circle or square pieces of glass?

Thanks for any input!

Check out this link...
Sears.com

There are other kits available as well. For $15, you can't go wrong.

G

Ive heard of laminating thin glass to a piece of paper, cardboard, or what have you, then using the sharpest cutting bit you can find and a dremel. But I would go with the saw bits Gadget linked to before trying that.

I like that hole saw set, thanks. Clearly, I need to stop buying laser parts and buy some tools instead, starting with a drill press.

Marco,
Mind you, the sizes are the bore size of the hole created, not the 'plug' removed.
And, use A LOT of water to keep things cool. Search for info on Lapidary supplies like corundum grit for shaping and polishing. If nothing else, use water and 600 grit wet/dry sand-paper to clean up the edges.

Depending on how many you need it might be worth paying a local glass house a few bucks to do it for you.

I think it would be a lot easier, faster, and cheaper to use a $4 glass cutter to get squares instead.

123splat said:

Marco,
And, use A LOT of water to keep things cool.

Click to expand...

YES...this! Water and lots of it. In fact, it's best done under running water because not only is it coolant, but it keeps the ground up glass washed out of the kerf.

Another tip...lay your glass on some kind of rigid backing (I like Styrofoam) for drilling.

G

+good luck with all those ideas--


I knew you would hear from Gadget- he has more experience than I do..



MP-- Is there room for a bigger round filter- that is- fitting over the apeture but not being down inside the place made for it?
That is why some have asked why not square-

If you can use 9.5 mm I may be able to help-- PM coming if I can..
I am now looking at the IR filter down inside a green (dead) labby- and they have glued at the corners a sqaure IR filter- looks like 3mm max- hard to measure and likely impossible to get out.

I do have an extra round filter but as i said its a tad more than 9mm(3/8th inch) Techhood sells @ $10 IIRC 10mm square filters maybe you coukd cut it in half twice and get 5 mm Sq. but cutting any small glass/filter/ mirror is not easy and harder for a round cut.

I had hopes that the diamond bits (used) my dentist gave me to make cutting down the Kasio Dichros mirrors as they are quite big- I was using a dremel-to make the scratch

it was not any easier than with a quality cutter w/ a tiny bit of oil on the wheel- I use the handle type with oil resivour-- I have a 'EZ cut' circle cutter than can scratch down to 3/8ths inch but anything smaller than .5 inch is hard with most items i am cutting

lumia wheels and FS mirrors for Spiro)

looking into round (#5) front surface dental mirrors.
- waiting for a free sample- the seller did not know- 12 pcs for $12

hope they are FS & have little loss--

:beer:hk

Bumping update & a question

Had a go at that IF filter in the dead 532 lab- (pic in post above)Managed to get it out with one chipped corner- the glue side of the filter faced the outgoing beam- ;; not sure that matters- front-back ?? it DOES for dichro filters- as on many only one side reflects- the other passes- certain wavelengths--

I used the tip of a new xacto blade & kept trying to get the glue out ecpept what was actually between the glass and the base- I looked for the corner with the least glue and was able to pry it up. I considered pushing with a wood dowel from the other side but that risks scratching the filter and/or breaking it -the glue was more like rubber cement -

So MP if you want it I can send in a 47 cent letter--

the Q is 'does it matter which side of an IR filter you pass thru??

and some also asked if all are the same- I.E. Is a IR filter form other DPSS like 473- same exact filter- same AR coating IF there is any ?? TY for help with the answers

MP PM COMING

hak

filter INSIDE the 'lens nut'? never saw any like that- you say 6mm - this is 5X5 and maybe close to 6 mm corner to corner---GL

Thanks for the replies all, especially Hak.

The laser in question is a modified 301 DPSS that I got more than a year ago. It's the cleanest 532nm laser that I have, perfect TEM00 output, very bright and stable. I think the older 301's were a lot better quality than what they're selling today.

The lens is the first element out of my dead Skylaser 405's 3-element, and is AR coated and works well. I figured it would be interesting to put an IR filter on it. The main issue is lack of the right tools to cut down larger glass pieces without tearing up the surfaces. I did find a vendor which sells, as luck would have it, 6mm and 7mm circular IR filters, but, they are discontinued, which is irritating because I'd have to order a few of them "just in case."

If not in the lens barrel I would put the filter behind the AixiZ module, glued over the hole where the laser diode would normally go. It's an M11 thread so 11mm diameter, but threading into the brass dpss module, so should allow for a ~7-ish mm or smaller square piece to fit there. I think most commercial modules put the filter between the expander and the collimator, so that would probably work. If you really don't mind sending me the IR filter I would be happy to give it a try and report the results :beer:

I'm curious as to what a reflective filter would do, though, sending that IR back into the cavity. Either more green output, or else blow up my laser. Or maybe nothing would change. I have three lasers to test it, maybe I should. I think the vast majority of them are the absorptive kind, i.e. the little blue piece of glass.