Nonlinear absorption in InN under resonant- and non-resonant excitation

Hyeyoung Ahn*, M. T. Lee, Y. M. Chang, J. L. Peng, S. Gwo


研究成果: Conference contribution同行評審


We report the wavelength-dependent nonlinear absorption (NLA) of InN film grown on anr-plane sapphire by molecular beam epitaxy technique. In order to understand the nonlinear optical properties of InN, the Z-scan measurement was performed at two different wavelengths, the photon energies of which are near (resonant excitation) and much higher (non-resonant excitation) than the bandgap of InN, respectively. Under non-resonant excitation, band-filling effect leads the dominant saturable absorption, while under resonant excitation, reverse saturable absorption dominates the nonlinear absorption. From the open-aperture Z-scan measurement under resonant excitation, we found that InN exhibits more than one nonlinear absorption process simultaneously. Particularly, under relatively weak resonant excitation, the transformation from saturable absorption to 2PA through the intermediate excitation state absorption was observed as the sample approaches the beam focus. The close-aperture Z-scan signals of InN show valley-peak response, implying that the nonlinear refraction in InN is caused by the self-focusing of the Gaussian laser beam. Using the Z-scan theory, the corresponding nonlinear parameters, such as saturation intensity, 2PA coefficient, and nonlinear refractive index, of InN were estimated.

主出版物標題Gallium Nitride Materials and Devices VIII
出版狀態Published - 12 6月 2013
事件SPIE Symposium on Gallium Nitride Materials and Devices VIII - San Francisco, CA, United States
持續時間: 4 2月 20137 2月 2013


名字Proceedings of SPIE - The International Society for Optical Engineering


ConferenceSPIE Symposium on Gallium Nitride Materials and Devices VIII
國家/地區United States
城市San Francisco, CA


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