We studied the factors of output-power fluctuation of the optical E-field sensor using LN optical modulator.
As a result, the output-power fluctuation factors are optical interference due to the cross talk of the optical circulator in
addition to input optical power of the photodiode.
Improving the factors, this sensor obtained excellent performance of output-power fluctuation of 0.009dB.
Uncertainty in E-field measurement using optical E-field sensor will be improved by it.