- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
High-speed femtosecond laser plasmonic lithography and reduction of graphene oxide for anisotropic photoresponse
摘要： Micro/nanoprocessing of graphene surfaces has attracted significant interest for both science and applications due to its effective modulation of material properties, which, however, is usually restricted by the disadvantages of the current fabrication methods. Here, by exploiting cylindrical focusing of a femtosecond laser on graphene oxide (GO) films, we successfully produce uniform subwavelength grating structures at high speed along with a simultaneous in situ photoreduction process. Strikingly, the well-defined structures feature orientations parallel to the laser polarization and significant robustness against distinct perturbations. The proposed model and simulations reveal that the structure formation is based on the transverse electric (TE) surface plasmons triggered by the gradient reduction of the GO film from its surface to the interior, which eventually results in interference intensity fringes and spatially periodic interactions. Further experiments prove that such a regular structured surface can cause enhanced optical absorption (>20%) and an anisotropic photoresponse (~0.46 ratio) for the reduced GO film. Our work not only provides new insights into understanding the laser-GO interaction but also lays a solid foundation for practical usage of femtosecond laser plasmonic lithography, with the prospect of expansion to other two-dimensional materials for novel device applications.
关键词： graphene oxide,photoreduction,anisotropic photoresponse,femtosecond laser,plasmonic lithography
更新于2025-09-23 15:19:57
-
Plasmonic interference lithography by coupling the bulk plasmon polariton mode and the waveguide mode
摘要： Plasmonic lithography based on surface plasmon polariton has been proven to breaking the diffraction limit and deliver the super-resolution patterns. However, most previously reported studies suffer from the low energy efficiency and subwavelength excitation grating which obstruct the application in nanofabrication. In this work, a special plasmonic lithography prototype is proposed based on the coupling of the bulk plasmon polariton (BPP) mode squeezed through the hyperbolic metamaterial (HMM) and the waveguide mode supported in the Coupling layer/HMM/PR (photoresist) sandwich structure. The results demonstrate that periodic patterns with strong lithography light intensity (>220%) over the whole photoresist layer compared with incident optical intensity, high aspect ratios (1.5:1) and a half-pitch of 57.5 nm can be generated, under the interference of the fourth-order diffracted light of grating. The lithography linewidth can reach 1/16 of the mask period of 920 nm and ~1/8 of the wavelength of the 436nm illumination light. This design of period reduction makes the device fabrication much easy, costless and even exhibits good tolerant to the roughness of the multilayer. In addition, theoretical analyses performed are widely applicable to systems working at other ultraviolet wavelengths including 248, 365 and 405 nm.
关键词： hyperbolic metamaterial,bulk plasmon polariton,waveguide mode,plasmonic lithography,surface plasmon
更新于2025-09-12 10:27:22