Gain-coupled optical logic in semiconductor lasers.
A new form of optical logic device has been devised giving NOT, NOR and NAND functions. It is based on gain competition between two optical modes in a semiconductor waveguide cavity. These modes are spatially separated at the input-output facet providing high input/output isolation. The input also sees very low reflection. Although the device relies on changes in carrier level, the switching speed is much greater than the carrier lifetime, with values of 70 to 100 ps being expected with multiquantum well devices. The device should have fan-outs of 5 to 15 and be fully cascadable. Because the input is not injected into a Fabry-Perot cavity, it is not wavelength sensitive.
Gallagher
D F
DF