Optical and Quantum Electronics

, Volume 43, Issue 1, pp 49–58

Saturable and reverse saturable absorption in aqueous silver nanoparticles at off-resonant wavelength

  • Misha Hari
  • S. Mathew
  • B. Nithyaja
  • Santhi Ani Joseph
  • V. P. N. Nampoori
  • P. Radhakrishnan
Article

DOI: 10.1007/s11082-011-9502-7

Cite this article as:
Hari, M., Mathew, S., Nithyaja, B. et al. Opt Quant Electron (2012) 43: 49. doi:10.1007/s11082-011-9502-7

Abstract

Silver nano-colloid was prepared by chemical reduction method and its nonlinear absorption properties were investigated by using open aperture z-scan experiment with nanosecond laser pulses operating at 532 nm. Interestingly, a switch over from saturable absorption to reverse saturable absorption was observed when the input intensity is increased from 28.1 to 175.8 MW/cm2. The underlying mechanism responsible for the observed switching behaviour is the interplay between ground state plasmon band bleaching and excited state absorption. Theoretical fitting was done by using a model in which nonlinear absorption coefficient as well as saturation intensity are incorporated.

Keywords

Silver nanocolloid Surface plasmon resonance Z-scan Third order optical nonlinearity Saturable absorption Reverse saturable absorption Two-photon absorption 

Copyright information

© Springer Science+Business Media, LLC. 2011

Authors and Affiliations

  • Misha Hari
    • 1
  • S. Mathew
    • 1
    • 2
  • B. Nithyaja
    • 1
  • Santhi Ani Joseph
    • 1
  • V. P. N. Nampoori
    • 1
  • P. Radhakrishnan
    • 1
    • 2
  1. 1.International School of PhotonicsCochin University of Science and TechnologyCochin-22India
  2. 2.CELOS, Cochin University of Science and TechnologyCochin-22India