Simultaneous Generation of Arbitrary Assembly of Polarization States for On-Chip Quantum Information Technology

Manipulating the polarization of light with metasurfaces is essential for integrated photonics and quantum information technology. Here we report on simultaneous generation of different types of polarization states with a single piece of metasurface. By introducing geometrical-scaling-induced phase modulations, we demonstrate that both circularly polarized and linearly polarized states can be simultaneously generated by a metasurface made of L-shaped resonators with different geometrical features. Upon illumination, each resonator diffracts the CP state with a certain GSI phase. The interaction of these diffractions leads to the desired output beams, where the polarization state and the propagation direction can be accurately tuned by selecting the geometrical shape, size, and resonator sequence in the unit cell. We also demonstrate that an image can be encoded with different polarization profiles at different diffraction orders and decoded with a polarization analyzer. This approach resolves a challenging issue in integrated optics and on-chip quantum information processing.
Reference:
Y.-J. Gao, X. Xiong, Z. Wang, F. Chen, R.-W. Peng, and Mu Wang, Phys. Rev. X 10, 031035 (2020).