Deep-UV optical gain has been demonstrated in Al0.7Ga0.3N/AlN multiple quantum wells under femtosecond optical pumping. Samples were grown by molecular beam epitaxy under a growth mode that introduces band structure potential fluctuations and high-density nanocluster-like features within the AlGaN wells. A maximum net modal gain value of 118 cm-1 has been measured and the transparency threshold of 5 microJ/cm2 was experimentally determined, corresponding to 1.4 x 1017 cm-3 excited carriers. These findings pave the way for the demonstration of solid-state lasers with sub-250 nm emission at room temperature.
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Sub-250nm room-temperature optical gain from AlGaN/AlN multiple quantum wells with strong band-structure potential fluctuations
E. F. Pecora, W. Zhang, A. Nikiforov, L. Zhou, D. Smith, J. Yin, R. Paiella, L. Dal Negro, T. D. Moustakas
Applied Physics Letters, 100, 061111 (2012) -
Polarization Properties of Deep-UV Optical Gain in Al-rich AlGaN Structures
E. F. Pecora, W. Zhang, J. Yin, R. Paiella, L. Dal Negro, T. D. Moustakas
Applied Physics Express 5, 032103 (2012) -
Sub-250nm light emission and optical gain in AlGaN materials
E. F. Pecora, W. Zhang, A. Yu. Nikiforov, J. Yin, R. Paiella, L. Dal Negro, T. D. Moustakas
Journal of Applied Physics 113, 013106 (2013) -
Development of AlGaN-based GRINSCH deep UV emitters by Molecular Beam Epitaxy
H. Sun, J. Woodward, J. Yin, A. Moldawer, E. F. Pecora, A. Yu. Nikiforov, L. Dal Negro, R. Paiella, K. Ludwig Jr., D. J. Smith, T. D. Moustakas
Journal of Vacuum Science and Technology B 31, 03C117 (2013) -
Deep-UV optical gain in AlGaN-based graded-index separate confinement heterostructure
E. F. Pecora, H. Sun, L. Dal Negro, T. D. Moustakas
Optical Materials Express 5, 809 (2015)