By using a combination of FILT, PSTN and prisms, I have found a way to store a value between zero and nine in a block of FILT/INSL matrix.

ROM proof of concept:

Which requires Heat Sim, or else the reading laser will melt and burn. Any ideas on how to implement a RAM device using this technology/ build a laser that can be toggled without heat sim?

Data Density: 10/4