1. G. H. B. Thompson, Physics of Semiconductor Laser Devices, John Wiley, Chichester (1980)
2. Tran fan Muoi, Laser Focus/Electro-Optics, October issue p 177 (1984)
3. Proc. of AGARD Conference on Digital Optical Circuit Technology, Schliersee, Germany (1984) to be published
4. C. Klingshirn and H. Haug, Phys. Rep. 70:315 (1981)
5. K. Unger, Z. Physik 207:322 and 332 (1967)