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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 20, Iss. 4 — Feb. 13, 2012
  • pp: 4518–4524

Terahertz emission from Indium Oxide films grown on MgO substrates using sub-bandgap photon energy excitation

Elmer S. Estacio, Christopher T. Que, Fritz C. B. Awitan, Jan Isaac Bugante, Francesca Isabel de Vera, Jonathan Azares, Jessica Afalla, Jeffrey de Vero, Armando S. Somintac, Roland V. Sarmago, Arnel A. Salvador, Kohji Yamamoto, and Masahiko Tani  »View Author Affiliations

Optics Express, Vol. 20, Issue 4, pp. 4518-4524 (2012)

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Indium oxide (In2O3) films grown by thermal oxidation on MgO substrates were optically excited by femtosecond laser pulses having photon energy lower than the In2O3 bandgap. Terahertz (THz) pulse emission was observed using time domain spectroscopy. Results show that THz emission saturates at an excitation fluence of ~400 nJ/cm2. Even as two-photon absorption has been excluded, the actual emission mechanism has yet to be confirmed but is currently attributed to carriers due to weak absorption from defect levels that are driven by a strain field at the interface of the substrate and the grown film.

© 2012 OSA

OCIS Codes
(310.6860) Thin films : Thin films, optical properties
(300.6495) Spectroscopy : Spectroscopy, teraherz

ToC Category:
Thin Films

Original Manuscript: January 11, 2012
Revised Manuscript: February 2, 2012
Manuscript Accepted: February 2, 2012
Published: February 8, 2012

Elmer S. Estacio, Christopher T. Que, Fritz C. B. Awitan, Jan Isaac Bugante, Francesca Isabel de Vera, Jonathan Azares, Jessica Afalla, Jeffrey de Vero, Armando S. Somintac, Roland V. Sarmago, Arnel A. Salvador, Kohji Yamamoto, and Masahiko Tani, "Terahertz emission from Indium Oxide films grown on MgO substrates using sub-bandgap photon energy excitation," Opt. Express 20, 4518-4524 (2012)

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