A scheme of measurement of quantum-vacuum geometric phases in the   noncoplanar fibre system
  We study the quantum-vacuum geometric phases resulting from the vacuum fluctuation of photon fields in Tomita-Chiao-Wu noncoplanar curved fibre system, and suggest a scheme to test the potential existence of such vacuum effect. Since the signs of the quantum-vacuum geometric phases of left- and right- handed (LRH) circularly polarized light are just opposite, the total geometric phases at vacuum level is inescapably absent in the fibre experiments performed previously by other authors. By using the present approach where the fibre made of gyroelectric media is employed, the quantum-vacuum geometric phases of LRH light cannot be exactly cancelled, and may therefore be achieved test experimentally. 
Jian Qi Shen