Surface plasmon polariton assisted optical switching in noble bimetallic nanoparticle system

Abstract

Photoresponse of bimetallic Au-Ag nanoparticle embedded soda glass (Au-Ag@SG) substrate is reported for surface plasmon assisted optical switching using 808 nm excitation.Au-Ag@SG system is made by an ion beam technique where Ag + is introduced first in the soda glass matrix by ion exchange technique. Subsequently 400 keV Au + is implanted in the sample for different fluences which is followed by an ion beam annealing process using 1MeV Si + at a fixed fluence of 2E16 ions.cm -2 . Characteristic surface plasmon resonance (SPR) peaks around 400 and 550 nm provided evidence for the presence of Au and Ag nanoparticles. An optical switching in the Au-Ag@SG system with 808 nm, which is away from the characteristic SPR peaks of Ag and Au nanoparticles, suggests the possible role of TPA owing to the presence of interacting electric dipole in these systems. The role of surface plasmon polariton is emphasized for the propagation of electronic carrier belonging to the conduction electron of Au-Ag system in understanding the observed photoresponse. Unique excitation dependent photoresponse measurements confirm the possible role of TPA process.A competitive interband and intraband transitions in the bimetallic system of Au and Ag with 2 may be primarily responsible for the observation, which are validated qualitatively using finite difference time domain calculations where inter-particle separation of Au and Ag play an important role. Thus, a smart way of optical switching can be envisaged in noble bimetallic nanocluster system where long wavelength with higher skin depth can be used for communication purpose.

Far field photoluminescence imaging of single AlGaN nanowire in the sub‐wavelength scale using confinement of polarized light

“…The nanoscale imaging in the sub‐wavelength limit was boosted with the application of plasmonics. Surface plasmon resonance (SPR), originating from the coherent oscillation of conduction electrons of noble metal nanoclusters excited by visible light, facilitates propagation of surface plasmon polaritons (SPP) along metal‐dielectric interface. The evanescent waves near to the metal‐dielectric interface assist the imaging or focusing of nanostructures in the sub‐diffraction length scale.…”

Surface Plasmon Polariton Assisted Optical Switching in Noble Metal Nanoparticle Systems: A Sub-Band Gap Approach

“…The same mechanism was proposed for the propagation of electronic carrier belonging to the conduction electron of noble bimetals in the Au-Ag@SG system in understanding the observed photoresponse [40]. Contributions of interband and intraband transitions in noble metals and inter-particle separation were discussed in understanding the plasmonic coupling mechanism.…”

“…A collective effect of local field enhancement of the Au nanoclusters in combination with the increased light amplitude in resonant cavities formed between the surfaces of the optimally dense Au clusters embedded in the SiO 2 matrix in the percolation limit was made responsible for the experimental observations [9]. In a unique study, light induced electrical conduction was reported in randomly-distributed Cu nanoparticles with varying surface coverage on an optically transparent Si 3 N 4 [40]. At a percolation threshold of 64% metal coverage, an optical switching was recorded corresponding to the peak wavelengths of the peak SPR ( Fig.…”

“…13). The observation suggested possibility of optical switching in noble bimetallic nanocluster system where long wavelength with higher skin depth can be used for the communication purpose [40]. [40]@2015,Copyright©American Institute of Physics; Applied for permission) Fig.…”

“…The SHG in the Pt/Cu [38] and Ag/Cu [39] systems drew lot of attention. In a recent report photoresponse of bimetallic Au-Ag nanoparticle embedded soda glass (Au-Ag@SG) substrate was reported [40] for surface plasmon assisted optical switching using 808 nm excitation, which was away from the characteristic SPR peaks of Ag (~400 nm) and Au (~550 nm) nanoparticles. The observation suggested the possible role of TPA owing to the presence of interacting electric dipole in these systems.…”