The processes used to create these crystals involve 3D modeling software, clear optical crystal production and multi-photon absorption.
Multi-photon absorption is a process that involves focusing a laser beam to a spot (about one-tenth of the diameter of a human hair) within a block of optically perfect crystal. The laser then emits a short pulse beam and produces a tiny micro crack.
To draw more points, the laser is pulsed on and off. To make the beam move between points, it’s reflected from a mirror that is repositioned between pulses. The mirror is moved by computer-controlled motors, so many points can be drawn with great speed and accuracy. A typical design might use several hundred thousand points, or half a million isn’t unusual in a large block, each placed with 0.001 accuracy.
The glass itself must be clear optical crystal, since any ripples or bubbles would block or blur the laser. It’s also necessary to draw in layers, moving from rear to front of the glass, so that previous points don’t block the laser from drawing new ones.