My Dorkbot DC cohort Jon Singer sent me a link to a webpage of a buddy of his, a Croatian laser-hacker, who grew his own KDP (Monopotassium phosphate) crystals for use in a Nd:YAG laser. He had a time getting the crystals to grow, but was able to finally get some suitable growth and to find the right angle and alignment to get decent SHG and a pretty green beam. Apparently, this is not commonly and easily done with KDP, so it’s a bit of a triumph on this fellow’s part.

Homegrown KDP crystal and successful SHG attempt [Thanks, Jon!]