Marini A, García de Abajo F J
ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain.
ICREA-Institució Catalana de Recerca i Estudis Avançats, Passeig Lluís Companys 23, 08010 Barcelona, Spain.
Phys Rev Lett. 2016 May 27;116(21):217401. doi: 10.1103/PhysRevLett.116.217401. Epub 2016 May 26.
Manipulating and controlling the optical energy flow inside random media is a research frontier of photonics and the basis of novel laser designs. Here, we show that a metamaterial consisting of randomly dispersed graphene nanoflakes embedded within an optically pumped gain medium (rhodamine 6G) can operate as a cavity-free laser thanks to its extraordinarily low threshold for saturable absorption. The emitted light is self-organized into a well-determined spatial pattern, which depends on the graphene flake density and can be externally controlled through the optical pump. We provide different examples of tunable laser operation ranging from stable single-mode to chaoticlike behavior. Our metamaterial design holds great potential for the optical control of light amplification, as well as for the development of single-mode beam-engineered cavity-free lasers.
操控和控制随机介质内部的光能量流是光子学的一个研究前沿领域，也是新型激光设计的基础。在此，我们展示了一种由随机分散在光泵浦增益介质（罗丹明6G）中的石墨烯纳米片组成的超材料，由于其极低的可饱和吸收阈值，它可以作为无腔激光器运行。发射的光自组织成一种确定的空间模式，该模式取决于石墨烯片的密度，并且可以通过光泵浦进行外部控制。我们提供了从稳定单模到类混沌行为的可调谐激光运行的不同示例。我们的超材料设计在光放大的光学控制以及单模光束工程无腔激光器的开发方面具有巨大潜力。
