Main Question or Discussion Point
There are materials which block laser beams (or light globally) or weaken its intensity via shading i.e. a beam must have crossed a specific energy barrier in order to pass this shading where beams with less energy will fade and won't pass. The question is, is there a material or a type of shading which does the opposite? Meaning that it blocks beams with intensities higher than a specific barrier and allows those with less intensities (behaving like a low pass filter somehow), does this type of material exist?!