Drilling a hole in a first surface mirror

[kecked]

Anyone have ideas on how to drill a 1mm hole in a first surface mirror? Due to size constrains I need to do this to sample a beam used for illuminating a sample. It’s a reference beam so I. Figured to sample through the back of a turning mirror. I have no other location in the light path to sample the beam or I’d use beam splitter or glass slide. So ideas on how to drill a hole in the glass without hopping the rest of the surface. I can’t just scrap the silver section I need an actual hole.

So far cracked one in half and peeled the coating in another. I’m Illuminati ing with a led so can’t use half a mirror either. Tried taping mirror too.

 

[WizardG]

Diamond burr, as fast as you can spin it (bidding starts @ 10k RPM), underwater. Use very gentle presure. Let the diamond grit do the work. Tape, or something, to mask the mirror surface for protection. Bset Idea I've got.

 

[RedCowboy]

 

[farbe2]

If you have access to a high powered pulse laser: try to burn the coating away.
You could also paint the location where you want to have the hole beforehand, this would make it easier to destroy the coating.

 

[kecked]

Fabre do you think I can just avoid the hole and remove the coating to grab a reference signal? I was just afraid of back scatter from the return signal. What I have is light enters a telecentric lens. This hits the turning mirror and is reflected back from the object set at normal incident. I’m imaging this on a CMOS camera on the telecentric lens to measure reflectance. So I wanted to add a reference to the system for the led. Hence the hole. I could not find a space to put a beam splitter except this turning mirror and I figured if I capture light from the telecentric lens before it turns up I can avoid also grabbing the return reflection. I’m measuring 0.01% changes in intensity.

Unfortunately I won’t really know if I and getting the return reflection too without a hole.

So I have a 355nm 12kw 1khz laser. I could ablate the coating but doubt pop a hole . You know I might need to just use a blank and drill it and then coat it after. I’m only looking for 1mm hole or less. I’m using it like a spatial filter as well. Thinking to add a polarizer set as well as I may be doing MOkE later with a magnet.

I’m an idiot…..use a 90/10 beam splitter. Never mind. I have plenty of illumination light.

 

[farbe2]

I’m an idiot…..use a 90/10 beam splitter. Never mind. I have plenty of illumination light.

Even a "bad/cheap" mirror could work, as long as it got a polished back side.
Depends on how much light you actually need.

 

[kecked]

Here is what I settled on. A dichroic mirror high pass . I have 7nm filter on the camera so I just reflect the band I need and pass the rest. The led brightness should be linear releative to all the wavelengths. No holes!

 

[atomd]

Diamond burr, as fast as you can spin it (bidding starts @ 10k RPM), underwater. Use very gentle presure. Let the diamond grit do the work. Tape, or something, to mask the mirror surface for protection. Bset Idea I've got.

When cutting gratings in lab, we tend to blow the dust away constantly with dry nitrogen.

 

[kecked]

The dichroic worked best. No holes!

 

[Amak87]

I’m a glazier and I’ve been cutting glass since I was 10 years old. There’s some good info but DM me if you want professional advice on this. You need a diamond tip bit, proper cutting fluid and you’ll need to make a small pool for the fluid to stay in while drilling. Absolutely zero pressure and let the bit do the work. Tape the back side to prevent breaking though and chipping the glass.. but being so thin of material , and inexperienced, you’re going to break many before you get it right… I could do this for you if you wanted.. being 1mm hole, you’ll need to use a diamond coated spear tip glass/ceramic drill bit. Best to order it from a glazing supply company, maybe you can find one on eBay or AliExpress..

 

[Amak87]

Diamond burr, as fast as you can spin it (bidding starts @ 10k RPM), underwater. Use very gentle presure. Let the diamond grit do the work. Tape, or something, to mask the mirror surface for protection. Bset Idea I've got.

lol 100% wrong

 

[Amak87]

Here is what I settled on. A dichroic mirror high pass . I have 7nm filter on the camera so I just reflect the band I need and pass the rest. The led brightness should be linear releative to all the wavelengths. No holes!

Good idear!