I wonder if this can be used to build a 3D display? Since they can control propagation speed, you can control the intersection point of two laser pulses. Let'

I wonder if this can be used to build a 3D display? Since they can control propagation speed, you can control the intersection point of two laser pulses. Let's say that each pulse is not enough to excite some medium to emit a photon, but if you time both pulses to intersect at a specific point in space, the combined energy of both pulses could trigger the excitation so the medium emits a photon. You could even use the same laser to select the position, send the slow pulse first, then the fast one exactly right so they intersect at the spatial point where you want a "dot" to appear.