Polarization is a fundamental property of electromagnetic waves that plays a key role in many physical phenomena and applications. Schemes to manipulate it are revisited with the emergence of metasurfaces, which have brought multi\uffe2\uff80\uff90functionalities straightforwardly. However, this has come at the expense of design complexity that relies strongly on field theory. Here, an ingenious strategy of modular design is proposed to construct subwavelength multifunctional polarization control devices. Chiral metasurfaces with different handedness are first proposed and regarded as modules. The versatile polarization controller can thus be obtained with the combination of different modules. These experiments demonstrate that the well\uffe2\uff80\uff90designed polarization controller possesses reconfigurable functionality, and various broadband polarization and amplitude regulation functions with high efficiency including arbitrary linear polarization rotation, asymmetric transmission effect, neutral\uffe2\uff80\uff90density\uffe2\uff80\uff90like filter, polarization beam splitter, etc., can be readily realized just by changing the cascaded modules. The physical mechanisms of the versatile polarization controller and chiral metasurface modules are both guaranteed by the Fabry\uffe2\uff80\uff93P\uffc3\uffa9rot\uffe2\uff80\uff90like resonances, which are theoretically verified via the transfer matrix method. It is envisioned that the modular concept will be of great benefit to designing compact multifunctional polarization controllers. It is possible to control the source of recombination in the same sample of porous silicon by applying a cyclic sequence of hydrogenation\u2013oxidation\u2013hydrogenation processes and, consequently, switching on-demand between Shockley\u2013Read\u2013Hall and Auger recombinations.
Polarization is a fundamental property of electromagnetic waves that plays a key role in many physical phenomena and applications. Schemes to manipulate it are revisited with the emergence of metasurfaces, which have brought multi\uffe2\uff80\uff90functionalities straightforwardly. However, this has come at the expense of design complexity that relies strongly on field theory. Here, an ingenious strategy of modular design is proposed to construct subwavelength multifunctional polarization control devices. Chiral metasurfaces with different handedness are first proposed and regarded as modules. The versatile polarization controller can thus be obtained with the combination of different modules. These experiments demonstrate that the well\uffe2\uff80\uff90designed polarization controller possesses reconfigurable functionality, and various broadband polarization and amplitude regulation functions with high efficiency including arbitrary linear polarization rotation, asymmetric transmission effect, neutral\uffe2\uff80\uff90density\uffe2\uff80\uff90like filter, polarization beam splitter, etc., can be readily realized just by changing the cascaded modules. The physical mechanisms of the versatile polarization controller and chiral metasurface modules are both guaranteed by the Fabry\uffe2\uff80\uff93P\uffc3\uffa9rot\uffe2\uff80\uff90like resonances, which are theoretically verified via the transfer matrix method. It is envisioned that the modular concept will be of great benefit to designing compact multifunctional polarization controllers. It is possible to control the source of recombination in the same sample of porous silicon by applying a cyclic sequence of hydrogenation\u2013oxidation\u2013hydrogenation processes and, consequently, switching on-demand between Shockley\u2013Read\u2013Hall and Auger recombinations. Extensive application of clustering and classification algorithms shows the potential of a CNT-based sensor array in breathomics.