Full-Stokes parameters detection enabled by a non-interleaved fiber-compatible metasurface.

Polarization of the optical field determines the way of light-matter interaction, which lays the foundation for various applications such as chiral spectroscopy, biomedical imaging, and machine vision. Currently, with the rise of the metasurface, miniaturized polarization detectors have attracted extensive interest. However, due to the limitation of the working area, it is still a challenge to integrate polarization detectors on the fiber end face. Here, we propose a design of compact non-interleaved metasurface that can be integrated on the tip of a large-mode-area photonic crystal fiber (LMA-PCF) to realize full-Stokes parameters detection. Through concurrent control over the dynamic phase and Pancharatnam-Berry (PB) phase, different helical phases are assigned to the two orthogonal circular polarization bases, of which the amplitude contrast and relative phase difference can be represented by two non-overlapped foci and an interference ring pattern, respectively. Therefore, the determination of arbitrary polarization states through the proposed ultracompact fiber-compatible metasurface can be achieved. Moreover, we calculated full-Stokes parameters according to simulation results and obtained that the average detection deviation is relatively low at 2.84% for 20 elucidated samples. The novel metasurface exhibits excellent polarization detection performance and overcomes the limitation of the small integrated area, which provides insights into the further practical explorations of ultracompact polarization detection devices.