School of Electrical and Computer Engineering and Birck Nanotechnology Center, Purdue University , 1205 West State Street, West Lafayette, Indiana 47907, United States.
Weldon School of Biomedical Engineering, Purdue University , 206 S. Martin Jischke Drive, West Lafayette, Indiana 47907, United States.
Nano Lett. 2016 Apr 13;16(4):2471-7. doi: 10.1021/acs.nanolett.6b00034. Epub 2016 Apr 4.
Plasmonics has brought revolutionary advances to laser science by enabling deeply subwavelength nanolasers through surface plasmon amplification. However, the impact of plasmonics on other promising laser systems has so far remained elusive. Here, we present a class of random lasers enabled by three-dimensional plasmonic nanorod metamaterials. While dense metallic nanostructures are usually detrimental to laser performance due to absorption losses, here the lasing threshold keeps decreasing as the volume fraction of metal is increased up to ∼0.07. This is ∼460 times higher than the optimal volume fraction reported thus far. The laser supports spatially confined lasing modes and allows for efficient modulation of spectral profiles by simply tuning the polarization of the pump light. Full-field speckle-free imaging at micron-scales has been achieved by using plasmonic random lasers as the illumination sources. Our findings show that plasmonic metamaterials hold potential to enable intriguing coherent optical sources.
等离子体激元学通过表面等离激元放大使深亚波长纳米激光器成为可能，从而给激光科学带来了革命性的进展。然而，到目前为止，等离子体激元对其他有前途的激光系统的影响仍难以捉摸。在这里，我们提出了一类由三维等离子体纳米棒超材料实现的随机激光器。虽然密集的金属纳米结构通常由于吸收损耗而不利于激光性能，但在这里，激光阈值随着金属体积分数增加到约 0.07 而不断降低。这比迄今为止报道的最佳体积分数高约 460 倍。该激光支持空间限制的激光模式，并允许通过简单地调整泵浦光的偏振来有效地调制光谱轮廓。通过使用等离子体随机激光器作为照明光源，实现了微米级的全视场无斑点成像。我们的研究结果表明，等离子体超材料有可能实现有趣的相干光学光源。
