This work presents a novel approach for size-controllable synthesis of silver nanoparticles by ultra-fast pulse laser ablation of silver nitrate aqueous solution with a wavelength of 800 nm and a pulse width of 35 fs. The influence of laser pulse delay and ablated mono-crystal silicon substrate on the silver nanoparticles size distribution was analyzed by means of TEM morphology, SEM morphology, Energy Dispersive X-ray spectroscopy and surface-enhanced Raman spectroscopy. The experimental results show that: 1) As the laser pulse changes from single-pulse to double-pulse and the pulse delay increases from 400fs to 1000fs, the mean size of silver nanoparticles decreases while the average number of nanoparticles increases, making the size distribution more centralized when laser pulse irradiate silver nitrate solution directly. 2) Focusing the laser pulse on the solid-liquid interface, the number of silver nanoparticles produced by doublepulse is several times higher than that of single-pulse. With the increase of pulse delay, the number of nanoparticles increases firstly and then decreases, peaking at 400 fs, and obvious agglomeration occurs on the silicon substrate.
We carried out a comparative study on ablation threshold behavior of femtosecond laser twin double-pulse processing of typical transparent material, semiconductors and metallic materials. Based on the change of ablation area with pulse temporal separation (100 fs-15ps) under the same spatially distributed Gaussian beam, influence of pulse-separation on normalized double-pulse ablation threshold (which is normalized to the single-pulse ablation threshold) was demonstrated qualitatively. Special attention paid on the variation characteristics of normalized double-pulse ablation threshold in the sub-picosecond pulse-separation range, as well as its value in pulse-separations comparable or larger than the electron-phonon (or ion) coupling time. We show that the ablation threshold behavior of femtosecond laser twin double-pulse is strongly material-specie dependent, however, can be summarized in to several ones. The difference in ionization and/or deionization mechanisms for the non-metal compared is possibly the physical origins for the contrasted behavior of double-pulse ablation threshold.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.