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 type of dye laser operating in a single-mode optical fiber has been studied. The gain is produced by surrounding a tapered section of the fiber with laser dye. Interaction of the light in the fiber with the laser dye is achieved through the exposed evanescent field at the taper waist. Low lasing thresholds (25-65 mW) are obtained as a result of the high intensities at the taper waist. These tapered fiber dye lasers combine the advantages of a laser in fiber form with the wide spectral tuning ranges provided by laser dyes. Three experiments, demonstrating low-threshold operation of a grating tuned laser, an all-fiber ring laser, and cw lasing in tapered fiber dye devices, are presented.
