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Hierarchical micro/nanostructures have garnered considerable attention for their capabilities in light modulation, but the flexible fabrication of designed optical functional structures at both micro and nano scales remains challenging. Here, a polarization‐modulated patterned laser ablation method complemented by flowing liquid is proposed to fabricate hierarchical microgrooves featuring tunable cross‐sections and engraved surface nanostructures with controllable periods and orientations. The liquid‐assisted ablation counters the shielding effect of ablation debris through laser‐induced microjets, ensuring accurate control of the microgroove's shape by modulating the laser pattern in the focal plane. Simultaneously, the absence of debris also permits the consistent formation of laser‐induced periodic surface structures (LIPSS) across the microgrooves. The LIPSS's period and orientation can be finely adjusted by manipulating the pulse energy and polarization within the patterned laser spot, facilitating the adaptable creation of hierarchical micro/nanostructures for optical application needs. As a demonstration, blazed gratings featuring orientation‐customized LIPSS are fabricated, which exhibit polarization‐dependent diffraction efficiency. The laser fabrication technique offers a highly versatile solution for sculpturing shape‐controllable hierarchical gratings on hard‐to‐machine materials, paving the way for the swift production of customized optical elements. [ABSTRACT FROM AUTHOR]

Laser‐induced periodic surface structures (LIPSS) have become an important avenue towards surface nanopatterning and certain device applications due to their subwavelength feature size and versatility with different materials. However, the uncontrollable non‐uniformity in achievable nanostructures presents a limit towards its practical application. Here, a robust approach is proposed to obtain controllable nanostructures with long‐range order based on a new insight into one of the electromagnetic origins of nonuniformity of LIPSS, namely a half‐periodic mismatched optical enhancement (h‐MOE) effect. The h‐MOE effect originates from the interference enhancement of surface plasmon polaritons (SPPs) located between tips of every two adjacent ripples in laser scanning process. It is found that LIPSS can be self‐aligned and highly controllable if the h‐MOE effect is elaborately modulated through designed laser scanning strategies especially sequential scanning paths. The new laser nanopatterning approach based on h‐MOE demonstrates controllable patterning ability to theoretically infinitely large‐area super‐straight gratings, orientation‐controllable gratings, and half‐periodic mismatched nanohole arrays. [ABSTRACT FROM AUTHOR]

• Efficiently fabricating hierarchical nanotextured microgrooves through hybrid laser processing. • Producing uniform 1D nanogratings and 2D nanoholes on V-shaped microgrooves. • Laser interference and laser-SPPs interference contribute to the formation of those nanostructures. • Those nanostructures can engrave into many microgrooves within one scanning process. Functional surfaces with hierarchical micro-/nanostructures play a vital role in improving performances in emerging fields over the past decades. In this work, we propose a hybrid manufacturing method for efficiently fabricating hierarchical nanotextured microgrooves by combining fly cutting and femtosecond laser nanopatterning. Nanostructures, including nanogratings and nanoholes, can be uniformly generated in a V-shaped groove by controlling laser polarization. We experimentally study the influence of the laser parameters (laser fluence and effective pulse number) to investigate the morphological evolution of nanostructures in the V-shaped groove under laser irradiation. By theoretical calculations and analyses, we find that the interference between the incident and reflected laser is helpful for ablating the nanogratings. In addition, this interference can also couple with the laser-SPPs (surface plasmon polaritons) interference and form nanoholes. The results enrich the diversity of achievable laser-induced periodic surface structures on complex surfaces and provide a new way to efficiently fabricate large-area hierarchical micro-/nanostructures at low cost. [ABSTRACT FROM AUTHOR]