Extremely Small Bending Loss of Organic Polaritonic Fibers

Photonic circuits possess advantages over electronic circuits in energy consumption, speed, bandwidth, and resistance to electromagnetic wave interference. Conventional dielectric waveguides confine light by total internal reflection at the interface between the waveguide and the surrounding media. This chapter describes new approach for guiding and bending light at a micrometer scale with little bending loss. It uses single crystalline nanofibers of organic dye molecules as waveguides. Unlike conventional waveguide materials, organic dye crystals have large oscillator strength of the exciton transition, seemingly leading to large propagation loss due to absorption. The chapter describes experimental findings that nanofibers of organic dye thiacyanine function as the polariton waveguides with extremely small bending loss. It presents miniaturized photonic circuit components fabricated using TC nanofiber building blocks. The mechanism of the extremely small bending loss is analyzed by calculating the dispersion relation of straight nanofibers and the complex propagation constant of curved nanofibers.