receiving the digital data;

parsing the digital data into successive packets to be stored in the light transmissive optical data storage sandwich medium layer;

processing the successive packets (i) to select successive sets of wavelengths to be used in encoding successive pixels associated with the successive packets, and (ii) to identify a set of distinct pixel locations in the light-transmissive optical data storage medium layer corresponding to each distinct one of the successive sets of wavelengths, so that each distinct pixel location is associated with an assigned set of wavelengths;

for each selected set of the successive sets of wavelengths, (a) establishing a mask of the light-transmissive optical data storage medium layer to allow exposure only of pixel locations assigned to such selected set of the successive sets of wavelengths, and (b) exposing the light-transmissive optical data storage medium layer through the mask using light of such distinct one of the successive sets; and,

in the course of exposing the light-transmissive optical data storage medium layer, doing so in a manner wherein light standing waves are formed in the light transmissive optical data storage medium layer.