Cheng－Shang Chang and Duan－Shin Lee

　　Due to the recent advances in optical transmisson technologies, the trissmisson speed of the optical links is much faster than the switching speed of current electronic Internet routers. The challenge is then to find switch arrchitectures that scale with the transmission speed of fiber optics. There are two approaches for this. (i) The electrionic approach, and (ii)The optical approch. The electronic approach is to use parallel electronic devices to acquire the needed speedup for the fiber optics. On the other hand, the optical approach is to explore the possibility of bulding intelligent logic control directly with optical devices. The objective of this book is to introduce recent advances in switch architectures from both the electronic approch and the optical approach.