Sub-wavelength periodical grating structures on tungsten surface was fabricated by femtosecond laser whose central wavelength is 800 nm and the repetition rate is 1 kHz. The period of the structures was 349-620 nm when the laser incidence angle was 0 o-80 o . The formation of grating structures on tungsten was discussed by surface plasmon polaritons theory and the result of experiment showed a good agreement. The reflectance spectra of these grating structure was simulated by rigorous coupled wave analysis method. The enhanced absorbtion peak was closed to the grating period. This study gives a prospect of applications by femtosecond laser fabricating grating structures.%使用中心波长800 nm、重复频率1 kHz的飞秒激光,在金属钨表面斜入射下制备了亚波长周期光栅结构,在入射角为0o~80o时,光栅结构的周期为349~620 nm. 利用表面等离子体激元的理论分析了在钨表面制备光栅结构的过程,实验结果与理论符合较好. 利用严格耦合波分析方法计算了实验中得到的光栅结构的反射光谱,其吸收增强波长大小与光栅结构周期相近. 研究结果表明:利用飞秒激光可以在金属表面直接诱导周期可控的光栅结构,此光栅结构具有一定的应用前景.
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