Z-scan Measurement of Optical nonlinearities of ZnO thin film
碩士 === 國立交通大學 === 光電工程所 === 91 === By utilizing femtosecond Kerr Mode-Locked Ti:sapphire laser as Z-scan light source, we have studied intensity dependent nonlinear refractive index of the ZnO thin film growth by Laser-MBE epitaxy. The two photon absorption coefficient β=1905 cm/GW, the t...
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| Format: | Others |
| Language: | en_US |
| Published: |
2003
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| Online Access: | http://ndltd.ncl.edu.tw/handle/41037216486699195967 |
| Summary: | 碩士 === 國立交通大學 === 光電工程所 === 91 === By utilizing femtosecond Kerr Mode-Locked Ti:sapphire laser as Z-scan light source, we have studied intensity dependent nonlinear refractive index of the ZnO thin film growth by Laser-MBE epitaxy. The two photon absorption coefficient β=1905 cm/GW, the third order nonlinear refractive index γ= 2.1110-11cm2/W and the fifth order nonlinear refractive index σr=4.5110-20cm3 with 748nm-wavelength of incident laser. Compared with two-band model, γ is 2000 times larger than theoretical value this is owing to near two-photon resonance. Results of β dependent with incident wavelength reveal this two-photon resonance behavior and results of σr dependent with incident wavelength show that free-carrier is induced by free-excitons under a intense light source pumping. The results of γ dependent with incident wavelength also show two-photon resonance behavior and excitonic enhancement.
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