**6. Conclusion**

Two-step laser-texturing base procedure is proposed to make surface decoration and surface property control on the metal, plastic, and glass products. The femtosecond laser micro−/nano-texturing works as the first step to form the tailored textures onto the hard-coating die and the surface-treated mold. Using the polygonal geometric models, various emblems, symbols, images, fonts, and pictures are textured onto the die surface. In particular, the textured DLC-die has sufficient hardness and chemical stability for long-term usage in cold and warm conditions. The nitrogen supersaturated tools by the low-temperature plasma nitriding plays as a reliable die to be micro−/nano-textured by using the femtosecond laser processing. Different from the homogeneous ablation process of DLC-die, the polarization in laser texturing must be controlled to form the nanotextures onto the micro-textured surfaces. This nitrided die has sufficient hardness and chemical stability in fine machining and in hot imprinting.

The CNC-imprinting is utilized as the second step to transcribe the mother textures on the die and mold them to the product surfaces. The cold imprinting of textures onto metallic product works well to reproduce the tailored micro−/nanotextured on the DLC-die. In this mechanical imprinting, the grain-size effect on the micro-plastic flow of metallic work has an influence on the accuracy of reproducibility in nanotexturing. The warm imprinting onto polymer product is also available to reproduce the micro−/nano-textures.

Hot imprinting procedure is needed to transcribe the laser-textured die surface into the glass preform. The hydrophobic die surface profile is imprinted onto the glass preform; the hydrophilic glass surface changes to be hydrophobic. This hot imprinting procedure is improved to increase the dimensional accuracy in transcription of micro−/nano-textures and to duplicate the tailored die surface profile with synthesized periodic structure.

The laser-textured DLC-die can be widely utilized to make large-area imprinting even onto the curved product surface and to form the textured product surface with a high aspect ratio. The nitrided stainless steel die is utilized to form the mother textured die surface by using the laser-processing and mechanical finishing processes. Various applications are acceptable to the present approach for micro−/nano-texturing of industrial and medical products.
