Theoretical analysis of the force on the end face of a nano-filament   exerted by an outgoing light pulse
  The slight deformations observed upon transmission of a light pulse through a short length of a silica glass nano-filament offer the possibility of determining the momentum of light inside the filament. Using precise numerical calculations that take into account not only the electromagnetic momentum inside and outside the filament, but also the Lorentz force exerted by a light pulse in its entire path through the nano-waveguide, we conclude that the net effect of a short pulse exiting the nano-filament should be a pull force on the end face of the filament. 
Masud Mansuripur and Armis R. Zakharian
physics.optics physics.class-ph