Structural Dependence of Nonlinear Optical Properties in <tex>$TeO_2-PbO-GeO_2$</tex>

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J. Korean Ceram. Soc. > Volume 33(5); 1996 > Article

Journal of the Korean Ceramic Society 1996;33(5): 507.

$TeO_2-PbO-GeO_2$계 유리 내 비선셩 광학 특성의 구조 의존성

김원효, 허종, 김유성¹, 류선윤²

포항공과대학교 재료금속공학과 비정질 무기재료연구실
¹포항공과대학교 재료금속공학과 비정질 무기재료연구
²선문대학교 재료공학과

Structural Dependence of Nonlinear Optical Properties in $TeO_2-PbO-GeO_2$

ABSTRACT

Nonlinear optical properties of TeO2-PbO-GeO2 glasses were investigated and their correlation with struc-tural modification was investigated. Third-order nonlinear susceptibility $chi$, ranged between 5.0$times$10-13 esu and 10.7$times$10-13 esu which are approximately 20-40 times larger than that of silica glass. The glass with a composition of 85(80TeO2-20PbO)-15GeO2(mol%) seemed to provide an optimum compromise between $chi$and the stability against crystallization. Analyses of the Raman spectra suggested that these glasses are mainly composed of [TeO4] tbp, [TeO3]tp and [GeO4] tetrahedral structural units. It was concluded that the positive contribution of Pb2+ with high polarizability to $chi$ in TeO2-PbO glasses overwhelmed the negative influence due to the structural modification of [TeO4]tbplongrightarrow[TeO3]tp. On the other hand addition of GeO2 in TeO2-PbO-GeO2 glasses resulted in the decrease of $chi$ values. This behavior was attributed to the formation of [GeO4] polyhedra at the expense of [TeOn] polyhedra and Pb2+ ions which normally sowed a higher contribu-tion to $chi$ than [GeO4] polyhedra.

Key words: Nonlinear optical properties, Third harmonic generation, Raman spectra, Tellurite glasses