Development of spin-photonic devices requires the integration of abundant functions and the miniaturization of the elements. Pancharatnam-Berry phase elements have fulfilled these requirements and can be attained by using dielectric metasurfaces with subwavelength nanostructures. Here, we review some of our works on Pancharatnam- Berry phase elements and make an introduction of some integrated spin-photonic devices. We propose to integrate Pancharatnam-Berry phase lens into dynamical phase lens, which can be conveniently used to modulate spin states of photons. By integrating a Pancharatnam-Berry phase lens into a conventional plano-concave lens, we can obtain spin-filtering of photons. Moreover, we demonstrate that the generation of complex wavefronts characterized with different spin states can be implemented by the Pancharatnam-Berry phase lens. Further, based on the spin-dependent property of Pancharatnam-Berry phase element, we realize the three-dimensional photonic spin Hall effect with lateral and longitudinal spin-dependent splitting simultaneously. We foresee that this optical integration concept of designing Pancharatnam-Berry phase elements, which circumvents the limitations of bulky optical components in conventional integrated optics, will significantly impact multipurpose optical elements, particularly spin-based photonics devices.
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