Improving ellipticity detection sensitivity for the Q & A vacuum birefringence experiment

Sheng-Jui Chen, Hsien-Hao Mei, Wei-Tou Ni +1

Q & A (quantum electrodynamics test and search for axion) experiment was first proposed in 1994 and a 3.5 m high-finesse Fabry-Perot prototype detector extendable to 7 m has been b…