Plasmonic random lasers continue to generate significant interest in the fields of optics and photonics due to their improved performance. This owes to the greater scattering strength and enhanced local field offered by the plasmonic scatterers. However, absorption losses and fluorescence quenching are the major setbacks to plasmonic random lasers. Design of plasmonic random lasers with low threshold and enhanced emission intensity continues to be a challenging area of research. This paper demonstrates that the use of one-dimensional anisotropic plasmonic structures can help to overcome these limitations to a great extent by manipulating the spectral overlap between the scatterers and gain medium. A low threshold random lasing system has been experimentally realized in this context, using Ag nanorods with aspect ratio tuned to give optimal scattering and field enhancement. The optimal aspect ratios were deduced using FDTD simulations and incoherent random lasing was experimentally demonstrated at a low threshold of 116 µJ/cm² or 0.023 MW/cm². We also demonstrate through spatial coherence measurements that the bright emission from the plasmonic random laser enables speckle contrast reduction upto 0.034 with single pulse illumination.

由于其性能提高，等离子随机激光器在光学和光子学领域继续引起人们极大的兴趣。这归因于等离子体散射体提供的更大的散射强度和增强的局部场。但是，吸收损耗和荧光猝灭是等离激元随机激光器的主要挫折。具有低阈值和增强的发射强度的等离激元随机激光器的设计仍然是一个具有挑战性的研究领域。本文证明，通过控制散射体和增益介质之间的光谱重叠，使用一维各向异性等离子体结构可以在很大程度上克服这些限制。在这种情况下，已经通过实验实现了低阈值随机激光系统，使用调整了长宽比的Ag纳米棒来提供最佳散射和场增强。使用FDTD模拟推论出最佳纵横比，并在116 µJ / cm的低阈值下通过实验证明了非相干随机激光²或0.023 MW / cm ²。我们还通过空间相干性测量证明，等离激元随机激光的明亮发射使单脉冲照明的散斑对比度降低至0.034。