Dear Colleagues,

Metasurface is a planar structure composed of subwavelength structural units, which can flexibly control the phase, polarization and wavelength of light, and become hotspot in micro/nano-optics in recent ten years. Micro/nano fabrication can ensure people design and control the optical properties of matter at nano-scale, and build new optical devices. Reasonable characterization system is necessary to accurately reflect the texture morphology, ensure the quality of processing, streamline the process.

Presently, most representation methods are still traditional ones. Fractal method is limited to characterize the surface with fractal characteristics but present fractal mathematical models do not consider the functional characteristics of the surface. Motif method is difficult to extract 3D surface characterization parameters. The functional parameter set method is mainly used to characterize the specific topography, which is difficult to be applied to most other engineering surfaces. The typical 2D profilometer not only fails to reflect the morphological characteristics in the horizontal direction, but also makes it difficult to ensure that the probe traverses the peak and valley points of the measured topography. Ordinary 3D topographies often need to intercept samples and damage the tested parts.

Existing surface characterization systems and detection methods have shortcomings in parameter selection and measurement methods, and it is urgent to develop new detection and characterization method to evaluate the surface quality of micro-nano machining metasurface.

Researchers whose interested area falls in surface characterization method, micro/nano fabrication of metasurface, the relationship between surface feature and fabrication technique, surface characterization apparatus are welcome to contribute to this special issue.