1. See e.g.: Optical Nonlinearities and Instabilities in Semiconductors, ed. by H. Haug (Academic, San Diego 1988)
2. S. Schmitt-Rink, D.S. Chemla, D.A.B. Miller: Adv. Phys. 38, 89 (1989)
3. See e.g.: Optical bistability, Dynamic Nonlinearity and Photonic Logic, ed. by B.S. Wherrett, S.D. Smith (The Royal Society, London 1985)
4. H.M. Gibbs: Optical Bistability: Controlling Light with Light (Academic, Orlando 1985)
5. C.D. Poole, E. Garmire: Opt. Lett. 9, 356 (1984)