Optical vault: reconfigurable bottle beam by conically refracted light
  We employ conical refraction of light in a biaxial crystal to create an optical bottle for trapping and manipulation of particles. We show that by just varying the polarization of the input light the bottle can be opened and closed at will. We experimentally demonstrate stable photophoretic trapping and controllable loading and unloading of light absorbing particles in the trap. 
A. Turpin, V. Shvedov, C. Hnatovsy, Yu. V. Loiko, J. Mompart, and W.   Krolikowski
physics.optics