Polarization based tracking sensor

The polarization based tracking sensor is a spin-off from an automated, self-aligning, polarization measurement instrument. The sensor may be designed to operate in either of two modes subsequent to calibration. It may either mechanically track or provide read out tracking data without moving parts. A six-port polarization measurement circuit was designed and optimized. The polarization based tracking sensor utilizes three six-ports with relative orientations chosen in a prescribed way. Each member of this set of three six-ports is calibrated at various angles of incidence. The results of calibration for each direction of incidence are arranged in a look-up table, in the form of four Stokes vectors forming rows of the calibration matrix for that direction.