All-optical polarization-filtered subwavelength imaging in microwave regime via atom-based polarization holography

Polarization imaging is essential to reveal rich information of the vectorial nature of microwaves. However, selective imaging of specific polarization components with subwavelength resolution remains challenging. Here, we propose atom-based polarization holography for all-optical polarization-filtered subwavelength imaging in microwave regime. A kind of atomic polarization holograms is recorded through two-photon excited anisotropy in a four-level quantum system and its diffraction properties are characterized using Jones theory combined with optical Bloch equation. It is found that the polarization information of microwaves can be actively manipulated to holographic diffracted light fields. Moreover, polarization imaging of atom-based polarization holography with a spatial resolution of one-fortieth wavelength (λ/40) has been realized experimentally through microwave-to-optical conversion. The function of polarization filtering is demonstrated by optical holographic diffraction and the microwave component with specific polarization state can be selectively imaged from superimposed polarized microwaves. Our work is expected to enable applications in polarization filtering and subwavelength imaging. Polarization imaging reveals vectorial nature of microwaves, but selective imaging of specific polarization components with subwavelength resolution remains challenging. The authors propose atom-based polarization holography to optically filter microwave polarizations from complex mixed signals via holographic diffraction, achieving λ/40 imaging resolution.