Periodic metasurface structures processed with spatially shaped femtosecond laser: Fundamentals and Applications

We propose a mask-free approach of femtosecond laser nonablative processing to fabricate extremely long-range uniform periodic metasurface structures. A cylindrically focused femtosecond laser efficiently produce large-area periodic modifiedstripes, then, the modified-stripes act as fine etch stops to generate desirable structures on sample surfaces during the subsequent chemical-etching process. The diffraction efficiency of the incident light could be flexibly tuned. This morphology-controllable periodic surface structures may facilitate application prospects in broad fields, such as optical communications, optical sensors, etc.