Physics seminar
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Physics seminar, 26 October Wednesday, 14:40, FASS G022

Speaker: Assoc. Prof. Dr. Ismail Karakurt

From: Işık University, Dept. of Physics


Nonlinear, near field absorption effects in VO2 thin films on microstructured


Vanadium dioxide is one of the most studied transition metal oxides due to its
reversible thermochromism. It undergoes a semiconductor-metal phase transition
(SMT) at a critical temperature Tc of 68 oC. The material is a semiconductor
below the critical temperature while above Tc it is a metal. Optical properties
of the oxide, as well as the electrical properties, change upon the phase
transition. The transmission through VO2 films decreases dramatically in the
metallic state in the infrared region. Another property which makes VO2
attractive for applications is that the phase transition can also be induced
optically by a laser. While optical nonlinearities of VO2 nanoparticles and
thin films have been demonstrated, nonlinear effects has not to our knowledge
been demonstrated in thin film structures with well-defined curvature In this
talk, I will present optical transmission measurements which demonstrate how
nonlinear, near-field absorption effects can be utilized to implement a planar
microstructured optical switch.

Contact: Emrah Kalemci,
    or      Cem Çelebi,