Optical nonlinearities and the ultrafast phase transition of VO 2 nanoparticles and thin films

Rene Lopez, Richard F. Haglund, Leonard C Feldman, Lynn A. Boatner, Tony E. Haynes

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Z-scan and pump-probe measurements with ultra-fast 800 nm laser pulses were used to compare the ultrafast third-order optical nonlinearities of VO 2 nanoparticles and thin films in both semiconducting and metallic states. It is found that when the samples are hold at temperatures above 67 °C in their metallic state, both nanocrystals and thin films present a positive intensity-dependent nonlinear index of refraction. In this metallic state the nanocrystals exhibit a saturable optical nonlinearity and enhancement of the nonlinear effects larger than those found in thin films. Below the transition temperature, the optical nonlinearities are more complex, since they arise from alterations in the VO 2 that arise both from the phase transition and from unrelated third-order nonlinear effects. Under these conditions, thin films exhibit a complete reversal to a negative nonlinear index of refraction while the nanocrystals, remarkably, show a smaller but still positive index. Pump-probe measurements on vanadium dioxide nanocrystals and thin films show they both exhibit an ultrafast response, undergoing the phase transition induced by a single laser shot in less than 120 fs. The speed of the solid-solid transformation, along with the striking reversal of the nonlinear properties across the phase transition, puts vanadium dioxide in a unique category among nonlinear materials.

Original languageEnglish
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
Volume6118
DOIs
Publication statusPublished - 2006
EventUltrafast Phenomena in Semiconductors and Nanostructure Materials X - San Jose, CA, United States
Duration: Jan 23 2006Jan 25 2006

Other

OtherUltrafast Phenomena in Semiconductors and Nanostructure Materials X
CountryUnited States
CitySan Jose, CA
Period1/23/061/25/06

Fingerprint

Phase transitions
Nanocrystals
nonlinearity
Nanoparticles
nanocrystals
Thin films
nanoparticles
thin films
Refraction
dioxides
Vanadium
vanadium
refraction
Pumps
pumps
probes
Superconducting transition temperature
shot
lasers
Laser pulses

Keywords

  • Nanoparticles
  • Nonlinear optics
  • Phase transition
  • Switching
  • Ultrafast
  • Vanadium dioxide

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics

Cite this

Lopez, R., Haglund, R. F., Feldman, L. C., Boatner, L. A., & Haynes, T. E. (2006). Optical nonlinearities and the ultrafast phase transition of VO 2 nanoparticles and thin films. In Proceedings of SPIE - The International Society for Optical Engineering (Vol. 6118). [61180O] https://doi.org/10.1117/12.640977

Optical nonlinearities and the ultrafast phase transition of VO 2 nanoparticles and thin films. / Lopez, Rene; Haglund, Richard F.; Feldman, Leonard C; Boatner, Lynn A.; Haynes, Tony E.

Proceedings of SPIE - The International Society for Optical Engineering. Vol. 6118 2006. 61180O.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Lopez, R, Haglund, RF, Feldman, LC, Boatner, LA & Haynes, TE 2006, Optical nonlinearities and the ultrafast phase transition of VO 2 nanoparticles and thin films. in Proceedings of SPIE - The International Society for Optical Engineering. vol. 6118, 61180O, Ultrafast Phenomena in Semiconductors and Nanostructure Materials X, San Jose, CA, United States, 1/23/06. https://doi.org/10.1117/12.640977
Lopez R, Haglund RF, Feldman LC, Boatner LA, Haynes TE. Optical nonlinearities and the ultrafast phase transition of VO 2 nanoparticles and thin films. In Proceedings of SPIE - The International Society for Optical Engineering. Vol. 6118. 2006. 61180O https://doi.org/10.1117/12.640977
Lopez, Rene ; Haglund, Richard F. ; Feldman, Leonard C ; Boatner, Lynn A. ; Haynes, Tony E. / Optical nonlinearities and the ultrafast phase transition of VO 2 nanoparticles and thin films. Proceedings of SPIE - The International Society for Optical Engineering. Vol. 6118 2006.
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