Surprising, but a monochromatic field can impart momentum "superkicks" to charged particles much greater than the momentum of a field photon.
"Superkicks near optical vortices" http://iopscience.iop.org/2040-8986/labtalk-article/55223 "Superweak momentum transfer near optical vortices" http://iopscience.iop.org/2040-8986/15/12/125701/pdf/2040-8986_15_12_125701.pdf "Optical currents" http://www.phy.bris.ac.uk/people/berry_mv/the_papers/Berry414.pdf Low mass particles, e.g. electrons, positrons, may acquire significant energy when present in an "optical vortex." When the field is wide-band, my guess is that the effect is even greater. -- Lou Pagnucco
