Abstract
We report on the efficient blue light emission from multiple quantum wells excited by femtosecond laser pulses with long wavelengths ranging from 1.24 to 2.48 μm. It is found that the trap states in GaN barrier layers lead to an efficient cascade multiphoton absorption in which the carriers are generated through simultaneous absorption of ( and 2) photons to the trap states, followed by simultaneous absorption of (, 4, and 5) photons to the conduction band. The dependence of the upconversion luminescence on excitation intensity exhibits a slope between and , which is in good agreement with the prediction based on the rate equation model.
© 2014 Optical Society of America
Full Article | PDF ArticleMore Like This
Guan-Lin Su, Thomas Frost, Pallab Bhattacharya, John M. Dallesasse, and Shun Lien Chuang
Opt. Express 22(19) 22716-22729 (2014)
M. H. Yuan, H. H. Fan, Q. F. Dai, S. Lan, X. Wan, and S. L. Tie
Opt. Express 23(17) 21909-21918 (2015)
Guanjun You, Jie Liu, Zhenyu Jiang, Li Wang, N. A. El-Masry, A. M. Hosalli, Salah M. Bedair, and Jian Xu
Opt. Lett. 39(6) 1501-1504 (2014)