double terminated quartz crystal

Folks, things are interesting to me. For example, why does an HDR use crystals to increase power. This is a double terminated quartz crystal that we use. Perhaps we will find out the answer. Yeah, some day very soon. Until then the experiments continue as we strive to understand the world around us.

Double terminated quartz crystals or DTs for short are important in my experience. They appear to be able to focus energy.