Building a 3.5 m prototype interferometer for the Q&A vacuum birefringence experiment and high-precision ellipsometry (original) (raw)

2004, Classical and Quantum Gravity

We have built and tested a 3.5 m high-finesse Fabry-Perot prototype inteferometer with a precision ellipsometer for the QED test and axion search (Q & A) experiment. We use X-pendulum-double-pendulum suspension designs and automatic control schemes developed by the gravitational-wave detection community. Verdet constant and Cotton-Mouton constant of the air are measured as a test. Double modulation with polarization modulation 100 Hz and magneticfield modulation 0.05 Hz gives 10 −7 rad phase noise for a 44-minute integration.