MyCrystalPortrait.com

Sub surface laser engraved crystal, also called laser etched crystal, is the process of burning an image below the surface of an optically perfect piece of crystal using a highly focused laser beam. Guided by a computer, the laser burns hundreds, or even thousands of dots, without disturbing the crystal surface, resulting in a 2d, 2 1/2d or 3d image that appears to be floating inside the crystal.

The creation of 3D laser engraved crystals utilize high-energy laser beams to produce a phenomenon known as multi-photon absorption within optically perfect crystal. This phenomenon, which uses the electromagnetic wave of the laser beam known as coherent light creates an electric field greater than 10 million volts per centimeter. When the laser beam is focused within the interior of the subject crystal the energy creates unattached electrons also known as “free” electrons. These “free” electrons, accelerated by the electric field created by the laser beam causes the high energy
electrons to collide with atoms and ions in the focus area. As the process continues it causes a chain reaction and produces about 1 million trillion free electrons per cubic centimeter in about 1 trillionth of a second. The laser then emits a short pulse beam of a few billionths per second and produces a tiny micro crack. The laser head then align and position tens of thousands of additional micro cracks to create 2 or 3 dimensional images.

Although, the laser generates power densities of 10 billion watts per square centimeter, the surface of the crystal is not damaged due to the highly transparent nature of optically perfect crystal. The resulting images appear to be suspended within the crystal.

As seen on Yahoo.ask