A proposal for full-field microwave polarization measurement in a Rydberg-atom mixer assisted by grating

A scheme of grating-assisted full-field (0°–180°) microwave (MW) polarization measurement is theoretically proposed using a Rydberg-atom mixer via electromagnetically induced transparency in the absence of a magnetic field. The probe spectrum reads out the mixed MW signal and is modulated by an optical grating. It is found that the multi-slit interference leads to the enhancement of the grating spectrum, which substantially enhances the distinguishability of MW polarization. The simulation result shows that the minimum resolvable polarization angle is about 0.04°, and the ratio of bandwidth-angle resolution is introduced to improve polarization measurement. Moreover, the MW field strength and the phase difference between local and signal MW fields could affect the symmetry of the grating spectrum, which helps to determine the polarization angles of the MW field from 0° to 180° without the aid of magnetic fields.