Working with YAG crystals can be tricky, and the right diamond drill for YAG makes a big difference in hole quality and avoiding micro-cracks. Drill geometry, grit, and coolant all matter.
A good reference for drills designed for photonics applications:
https://ukam.com/diamond-core-drills-tools-for-photonics-industry/
What drill sizes, speeds, and coolant setups have you found work best for clean, precise holes in YAG?
I don’t drill yag but I cut several varieties of yag. The ND yag is a easy type to work with. The CR yag is a little different. It seems to have several extremely hard areas and is definitely harder than ND yag. I confirmed this with the manufacturer. I get my yag directly from the company that grows it and produces laser rods mainly for the medical industry. The CR yag is what they call Ruby yag. It cuts amazing stones if you understand the hardness and sometimes pitting issues on a few facets. The pitting is usually easily fixed by a change of lap direction. The hardness issue is not as easily solved but patience and a gentle touch on the cutting laps and a very good prepolish then 100k on a ceramic lap seems to be the answer. I have not cut enough CTH YAG yet to give an in-depth description. But I intend to in the next few months. What are you making that requires drilling yag?