| Summary: | 碩士 === 國立臺灣海洋大學 === 光電科學研究所 === 101 === In this study, we used z-scan technique to measure a thin film of (Ba, La) SnO3 prepared on glass substrate. Its thickness was 200nm, and the (Ba, La) SnO3 thin film was fabricated by BaSnO3 for three different concentrations of Lanthanum such as 4.5at%, 5.0at% and 5.3at% and meant to measure nonlinear optical properties. The light resource of z-scan system applied Ti-sapphire laser while its impulse width was approximately 130 femtoseconds at a wavelength of 800 nm, and its repetition rate was 1 kHz.
By results of z-scan close aperture measurements, we could see that (Ba, La) SnO3 thin film remained self-focusing. The experiment results of nonlinear refractive index n2 with different doped concentrations of 4.5at%, 5.0at% and 5.3at% were respectively (1.2±0.3) ×10-10 (esu), (0.9±0.1) ×10-10 (esu) and (1.2±0.2) ×10-10 (esu). The third-order nonlinear susceptibility χ(3) with different concentrations of 4.5at%, 5.0at% and 5.3at% were respectively (3.7±1.1) ×10-19(m2/V2), (2.9±0.3) ×10-19 (m2/V2), and (3.9±0.5) ×10-19 (m2/V2).
By results of z-scan open aperture measurements, we could see (Ba, La) SnO3 thin film samples remained saturated absorptions. The experimental results of three-photon absorption coefficient α3 were respectively(5.7±0.4)×10-20 (cm3/W2), (5.0±0.2)×10-20 (cm3/W2) and (5.0±0.5)×10-20 (cm3/W2). The fifth-order nonlinear susceptibilities χ (5) with different concentrations of 4.5at%, 5.0at% and 5.3at% were(2.1±0.1)x10-36(m4/V4), (1.9±0.1)x10-36(m4/V4)and (2.2±0.2)x10-36 (m4/V4)
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