Improvement of phase shift signal to noise ratio in electrooptic field measurement methods

The electro-optic field measurement methods which are nonintrusive can be widely applied to gas, liquid and solid media, which are transparent to light and electrically birefringent. These methods are not adequately developed for practical electric fields, that is, nonuniform three-dimensional electric fields. We often encounter the difficulty of getting precise signals because these electro-optic methods must handle small signals with relatively large noise. In this paper, some effective methods of improving the phase shift signal to noise ratio in electro-optic field measurement methods are examined and discussed