Author(s)

Yuyin Wei, Furi Gao and Sumei Wang

Corresponding Author

Sumei Wang

ABSTRACT

Fiber Tips with different roughness are fabricated and deposited with silver nanoparticles for SERS detection. Firstly, femtosecond laser double pulses are used to improve the surface roughness of ablated fiber by adjusting the power，scan speed and the pulse-delay. Secondly, silver nanoparticles are reduced by laser-induced method on the fabricated optical fibers with different surface roughness. The size and distribution of silver nanoparticles deposited on rough surfaces are better than that on smooth surfaces, which attributes to that the micro- and nanostructure on the rough tip surface can make the adsorption of silver nanoparticles easier and enhance the intensity of laser field at the output end. The best deposition effect is achieved at 7 mW induced deposition power and 7.5 min deposition time. When the Ra is 0.331, the prepared SERS sensor has the best performance and the lowest detection concentration is 10-6M. The SERS sensor prepared by depositing silver nanoparticles on the rough fiber tip has good performance and broad application prospects.

KEYWORDS

SERS sensor; femtosecond laser; double-pulse fabrication