Pulsed laser deposition of metal films and nanoparticles in vacuum using subnanosecond laser pulses

Abstract

A study of silver, chromium, stainless-steel, and indium thin films prepared by subnanosecond laser deposition in vacuum is reported. We compare the laser ablation in vacuum at the weak- and tight-focusing conditions of a Ti:sapphire laser beam and analyze the nanoparticles synthesized in the latter case using absorption spectroscopy, x-ray fluorescence, atomic force microscopy, and scanning electron microscopy. Our results show that the nanoparticle formation can be accomplished using long laser pulses under tight-focusing conditions.

Efficient keV X-ray Generation from Irradiation of in-situ Produced Silver Clusters by Ti:sapphire Laser Pulses

“…Increasing the delay results in the arrival of more and more clusters in the interaction region of the main beam. The observed increase in absorption with increasing pre-pulse intensity is then simply understood from the increase in number as well as the velocity of clusters produced at higher pre-pulse intensity [19,20].…”

“…The reason of formation of clusters is the relaxation of material in extreme conditions via fragmentation and molten material ejection [16][17][18]. We have shown in our earlier experiments large cluster formation (size 10-80nm) using 300 ps laser pulses focused on various materials like Ag, Efficient keV X-ray Generation from Irradiation of in-situ Produced … -U. Chakravarty et al In, Cu etc [19,20], which may be used as targets for x-ray generation. In this paper we present a study of laser energy absorption of intense Ti: Sapphire laser pulses in such in situ produced clusters, and the x-ray generation from them.…”

“…In our previous work [19,20], we have studied cluster generation from solid target irradiation by sub-ns laser pulses from the debris deposition on a substrate (the details of the experimental setup are described in refs 19, 20). SEM pictures of the deposit taken at two prepulse intensities, one at 3×10 12 W/cm 2 and the other at 10 10 W/cm 2 , clearly revealed a much higher cluster density corresponding to the deposition taken at the higher intensity of the sub-ns pulse.…”

“…SEM pictures of the deposit taken at two prepulse intensities, one at 3×10 12 W/cm 2 and the other at 10 10 W/cm 2 , clearly revealed a much higher cluster density corresponding to the deposition taken at the higher intensity of the sub-ns pulse. The particle density in this case (I = 3×10 12 W/cm 2 ) was estimated to be ～100 particles/μm 2 from the SEM pictures [19,20]. In the work reported here, we carried out the absorption measurements of intense femtosecond laser pulses by these in situ produced clusters, using the experimental setup shown in Fig.…”

Ultra-intense Laser Plasma Interaction Studies at RRCAT, Indore

“…Although metal clusters and grating microstructures have been used for achieving high absorption and enhanced x-ray emission, such targets are produced separately. Recently, ablation driven by intense laser pulses has emerged as an alternate route for production of nanometer sized clusters 13) . It is interesting to explore the use of such clusters as targets for efficient absorption of high intensity ultrashort laser pulses, and intense x-ray generation.…”