Mixed two- and three-photon absorption in bulk rutile (TiO2) around 800 nm

Opt Express. 2012 Jan 30;20(3):3118-28. doi: 10.1364/OE.20.003118.

Abstract

We observe mixed two- and three-photon absorption in bulk rutile (TiO2) around 800 nm using the open aperture Z-scan technique. We fit the data with an extended model that includes multiphoton absorption, beam quality, and ellipticity. The extracted two- and three-photon absorption coefficients are below 1 mm/GW and 2 mm3/GW2, respectively. We observe negligible two-photon absorption for 813-nm light polarized along the extraordinary axis. We measure the nonlinear index of refraction and obtain two-photon nonlinear figures of merit greater than 1.1 at 774 nm and greater than 12 at 813 nm. Similarly, we obtain three-photon figures of merit that allow operational intensities up to 0.57 GW/mm2. We conclude that rutile is a promising material for all-optical switching applications around 800 nm.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Light
  • Materials Testing
  • Photons
  • Refractometry
  • Scattering, Radiation
  • Titanium / chemistry*

Substances

  • titanium dioxide
  • Titanium