That's what I am trying to figure too. Two coherent beams with the same frequency, and after adjustment for phase and amplitude, could be made to cancel simply

That's what I am trying to figure too. Two coherent beams with the same frequency, and after adjustment for phase and amplitude, could be made to cancel simply with destructive interference. Maybe this achieves something more, or maybe this does not require amplitude or phase adjustment. I do not know (and possibly do not know enough Physics to follow).