Transient saturation absorption spectroscopy excited near the band gap at high excitation

Transient saturation absorption spectroscopy excited near the band gap at high excitation carrier

density in GaAs

Wu Song-Jiang;Wang Dan-Ling;Jiang Hong-Bing;Yang Hong;Gong Qi-Huang;Ji Ya-Lin;Lu Wei

【期刊名称】《中国物理：英文版》 【年(卷),期】2004(013)001

【摘要】@@ Transient saturation absorption spectroscopy in GaAs thin films was investigated using femtosecond pump and supercontinuum probe technique at excitation densities higher than 1× 1019 cm-3. The Coulomb enhancement factor of the electron-hole plasma results in a spectrum hole at the pump wavelength. Two distinct transmission peaks at two sides of the pump wavelength are observed, arising from the bleaching of transitions from the heavy- and light-hole bands to the conduction band. The dynamic process of the transient saturation absorption is fitted using a bi-exponential function. The fast decay process is dominated by the carrier-phonon scattering and the slow process may be attributed to the electron-hole recombination. 【总页数】4页(111-114) 【

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saturation

absorption;supercontinuum;Coulomb

enhancement factor

【作者】Wu Song-Jiang;Wang Dan-Ling;Jiang Hong-Bing;Yang