1. P. A. M. Dirac, The Principles of Quantum Mechanics, 4th ed., pp. 9, Oxford University Press, London (1958).
2. R. Akimoto, B. S. Li, K. Akita, and T. Hasama, "Ultrafast intersubband optical switching in II-VI-based quantum well for optical fiber communications," phys. stat. sol. (b) 243, 805-812 (2006) 10.1002/pssb.200564715
3. Y. Li, A. Bhattacharyya, C. Thomidis, T. D. Moustakas, and R. Paiella, "Nonlinear optical waveguides based on near infrared intersubband transitions in GaN/AIN quantum wells," Opt. Exp. 15, 5860-5865 (2007) 10.1364/OE.15.005860
4. G. W. Cong, R. Akimoto, K. Akita, T. Hasama, and H. Ishikawa, "Low-saturation-energy-driven ultrafast all-optical switching operation in (CdS/ZnSe)/BeTe intersubband transition," Opt. Exp. 15, 12123-12130 (2007) 10.1364/OE.15.012123
5. Y. Fedoryshyn, P. Strasser, P. Ma, F. Robin, and H. Jackel, "Optical waveguide structure for an all-optical switch based on intersubband transitions in InGaAs/AlAsSb quantum wells," Opt. Lett. 32, 2680-2682 (2007) 10.1364/OL.32.002680