Surface plasmon amplification and active nonreciprocal gratings

摘要

In this paper, we review our recent work on active plasmonic structures composed of optically pumped dye molecules infiltrated in a polymer host as the cladding of long-range surface plasmon polariton (LRSPP) structures. In particular, concepts for distributed Bragg and distributed feedback (DBR/DFB) lasers, and a spatially non-reciprocal Bragg grating (NRBG) are reviewed. The LRSPP Bragg grating is a fundamental element in these devices which is created by stepping the width of a metal stripe to produce modulation of refractive index. The gain medium in all of these active devices is assumed to be a thin film (～1 μm) of polymer (poly (methyl methacrylate)) doped with organic laser dye molecules IR-140. The gain medium is assumed pumped optically through the top of the devices via 10 ns laser pulses at 810 nm with 500 kW/cm~2 power intensity to enable stimulated emission at 880 nm. The maximum material gain coefficient of this medium was measured independently as 68 cm~(-1).