Laser-Direct Writing of Silver nanostructure on Transparent Substrates by femtosecond laser with high SERS

We report a simple method for the laser direct writing of silver structures which are fabricated by using femtosecond laser (fs-laser) pulses on Transparent Substrates coating of Silver ion-doped Polyvinyl Pyrrolidone thin-film. In this work, we combine with photonic reduction to produce novel nanostructured substrates. By tuning the laser energy the substrates are demonstrated to exhibit three different kinds of structure which at first is silver nanowires, then is silver nanograting , finally is silver nanoparticles. Three different state have their own application . The obtained structures were analyzed by a scanning electron microscope . we use the nanoparticles as a surface-enhanced Raman scattering-active (SERS-active) substrates, such SERS substrates for chemisorbed p-thiocresol (pTc) molecules at 633 nm excitation wavelength was measured. This technique is an excellent means of providing sensitive substrates for SERS with capability of signal homogeneity, high sensitivity and chemical stability.