Baojun Li

By Xianguang Yang and Baojun Li

Surface plasmons are coherent electron oscillations behaving as localized and propagated modes in metal nanoparticles and nanowires, respectively. In this chapter, we first review some of the applications made in plasmonics with gold nanorods/nanospheres and silver nanowires. For gold nanoparticles with a size of 1–100 nm, the surface plasmons are confined around the particle surface as localized modes to enhance the near-field. For diameter of around 200–300 nm silver nanowires with a length up to 10 μm, the surface plasmons can propagate along the nanowires as waveguide modes to guide the plasmons. We then describe some novel results with regarding to gold nanorod enhanced light emission, silver nanowire supported plasmonic waveguide, gold nanosphere mediated whispering-gallery-mode emission, and energy conversion in silver-polymer plasmonic nanostructures. The work of this chapter highlights the applications of metal nanoparticles and nanowires in plasmonic waveguides to achieve optical energy generation, propagation, and conversion.

Part of the book: Plasmonics

By Yuchao Li, Heng Li, Xixi Chen, Tianli Wu and Baojun Li

In recent years, with the rapid development of micro/nano optics, biophotonics, and biomedicine, micro/nano optical devices have been widely used in biosensing, medical imaging, molecular diagnosis, and other fields due to their advantages of miniaturization and integration. However, micro/nano optical devices composed of semiconductor and precious metal materials are prone to irreversible physical damage to biological cells and tissues and require chemical synthesis, which cannot be naturally degraded in vivo. In addition, due to the limitation of solid materials, micro/nano optical devices are difficult to deform and move in practical applications such as optical imaging and signal detection. Therefore, it is necessary to find a natural, biocompatible, biodegradable, and controllable micro/nano optical device. During the evolution of nature, some organisms have formed bio-optical devices that can manipulate light beams. For example, algal cells have the ability to concentrate light, which can improve the efficiency of photosynthesis. Visual nerve cells have the ability to direct light and transmit images to the retina with low loss and distortion. These natural materials capable of light regulation bring new opportunities for biological micro/nano optical devices, which have potential applications in the assembly of biological cells, detection of biological signals, imaging in vivo, and single-cell diagnosis.

Part of the book: Advances in Nanofiber Research - Properties and Uses [Working title]