Recent Progress and Comment on Metasurface Devices based on Two-photon 3D Printing

Metasurface is a thin layer that composed of periodic subwavelength artificial structures. By vibrating together with the incident electromagnetic waves, it introduces the phase jump, which breaks the traditional dependence on spatial optical path accumulation and exhibits unique electromagnetic characteristics. Metasurface has attracted great interest during the past ten years due to its ultra-thin thickness, ultrashort modulation distance and manipulation of light with ultrahigh resolution, superior to traditional optical elements. As the two-dimensional counterpart of metamaterials, it is easier to manufacture and integrate into the devices with operating wavelength ranging from microwaves to visible. The manufacturing processes commonly used for metasurfaces include ultraviolet lithography, electron beam lithography, focused ion beam lithography and nanoimprinting. However, the mass application still faces contradictions between processing accuracy and mass manufacturing and processing costs. Two-photon 3-Dimensional (3D) printing technology which is based on femtosecond pulse laser and two-photon polymerization reaction can fabricate metasurface with high precision and complex 3D structure by only one-step lithography without mask. It has the merits of processing convenience and flexibility, and has the potential of large-scale manufacturing. Therefore, it is widely used in the study and fabrication of metasurface. The paper reviews recent researches on metasurface optical devices fabricated by two-photon 3D printing technologies. An introduction to the concept, advantages and processing methods of metasurface is presented firstly, followed by the principle, development, and technological advantages of two-photon 3D printing. Recent study on metasurface devices ranging from plasmonic metasurfaces, metalens, metasurfaces for nano-display and holography, and metasurfaces integrated into fiber facet are reviewed respectively. Finally, the discussion and comments on metasurface devices based on two-photon 3D printing are given.