Third order nonlinear optical susceptibility for transparent tin oxide thin films

Abstract

Third order nonlinear optical susceptibilities for transparent SnO₂ thin films were examined by a combined study on both the experimental evaluation of X⁽³⁾(−3ω:ω, ω, ω) and theoretical analysis of the electronic structure. The X⁽³⁾ of SnO₂ thin film was evaluated to be about 10⁻¹² esu from the measurement of the third harmonic generation. The origin of a large X⁽³⁾ for SnO₂ was interpreted as follows: the large mobility of optically excited electrons at the conduction band, which consists of spherically symmetric 5s orbital of Sn atoms, must contribute to the enlargement of dipole moment induced by optical excitation.

Key Words:

• nonlinear optics
• SnO₂ film
• THG
• electronic structure