Optical frequency domain polarimetry for distributed polarization crosstalk measurement beyond a 110 dB dynamic range

In this Letter, we present optical frequency domain polarimetry (OFDP), a novel, to the best of our knowledge, distributed polarization crosstalk (DPC) measurement method with a dynamic range beyond 110 dB. It is based on swept-wavelength interferometry using a tunable laser source (TLS) and a delay line interferometer (DLI). The ultrahigh dynamic range is achieved by optimizing the sweep rate of the TLS and the optical path difference of the DLI. Using OFDP, we measured polarization crosstalk below -105 dB in a LiNbO3 waveguide modulator for the first time. OFDP will play a significant role in developing and fabricating high-performance polarization devices. (C) 2022 Optica Publishing Group