In-Line High-Speed All-Fiber Polarimeter With True Real-Time Acquisition for Sensor Systems Based on Fast Polarization Rotation

We report on the detailed characteristics of an all fiber polarimetric optical detector based on tilted fiber gratings. Our device exhibits an RF bandwidth of 500 MHz and a single-calibration optical bandwidth of over 30 nm. We also show that the device has minimal PDL, PMD, and return loss. Finally, we show that the device may be calibrated using only random unknown input polarizations with DOP = 1 and constant or measured power. We demonstrate that our polarimeter can use a local metric of calibration validity in place of an absolute comparison to a reference polarimeter. We show that the total measurement time for an accurate calibration can be reduced to under 1 s. We integrated our polarimeter into an acquisition system capable of measuring fast polarization rotation events over long periods of time with 250 MS/s peak sampling rate.