ABSTRACT
We present a novel numerical scheme for the simulation of the field enhancement by metal nano-particles in the time domain. The algorithm is based on a combination of the finite-difference time-domain method and the pseudo-spectral time-domain method for dispersive materials. The hybrid solver leads to an efficient subgridding algorithm that does not suffer from spurious field spikes as do FDTD schemes. Simulation of the field enhancement by gold particles shows the expected exponential field profile. The enhancement factors are computed for single particles and particle arrays. Due to the geometry conforming mesh the algorithm is stable for long integration times and thus suitable for the simulation of resonance phenomena in coupled nano-particle structures.
ABSTRACT
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.
