Single-shot polarization mapping of optical elements introducing spatially varying birefringence

Abstract

Polarization mapping plays a key role in modern photonics, as many advanced optical applications, ranging from vector beam engineering to optical communication and material characterization, rely on precise knowledge of spatial polarization distributions. However, conventional mapping techniques often suffer from limitations such as multi-step measurements, sensitivity to misalignment, or the need for bulky setups, making single-shot and high-resolution polarization mapping particularly challenging. Here, we report a single-shot polarization mapping technique for parallel determination of the polarization change introduced by an unknown optical birefringent element or even device (e.g. q-plates, spatial light modulators). To achieve this, we used a 9\(\times \)9 array of linearly polarized probe sub-beams to capture spatially resolved polarization information in a single measurement, allowing the two-dimensional polarization distribution to be reconstructed from just one data acquisition step. In this way, the measurement time is reduced while high spatial resolution is preserved. To demonstrate the robustness of the technique, we present a measurement with commercially available polarizing vortex plates, which convert linearly polarized light into radially or azimuthally polarized light, and the determination of the polarization response of a commercially available spatial light modulator. The main advantage of the method is its simplicity, achieved without sacrificing efficiency, which makes it readily accessible to any laboratory.