Thresholdless coherent light scattering from subband polaritons in a strongly coupled microcavity

作     者：Johannes Gambari Antonio I. Fernandez-Dominguez Stefan A. Maier Ben S. Williams Sushil Kumar John L. Reno Qing Hu Chris C. Phillips 

作者机构：Physics Department Imperial College London London SW7 2AZ United Kingdom Department of Electrical Engineering California NanoSystems Institute University of California Los Angeles California 90095 USA Department of Electrical Engineering Computer Science and Research Laboratory of Electronics Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA Sandia National Laboratories Department 1123 MS 0601 Albuquerque New Mexico 87185-0601 USA 

出 版 物：《Physical Review B》 (Phys. Rev. B Condens. Matter Mater. Phys.)

年 卷 期：2010年第82卷第12期

页      面：121303(R)-121303(R)页

核心收录：

学科分类：0808[工学-电气工程] 0809[工学-电子科学与技术（可授工学、理学学位）] 07[理学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：Engineering and Physical Sciences Research Council, EPSRC, (EP/D063329/1, EP/G031819/1, EP/H000917/1, EP/H000917/2) Engineering and Physical Sciences Research Council, EPSRC 

摘      要：We study a “strongly coupled (SC) polariton system formed between the atomlike intersubband transitions in a semiconductor nanostructure and the terahertz optical modes that are localized at the edges of a gold aperture. The polaritons can be excited optically, by incoherent excitation with band-gap radiation, and we find that they also coherently scatter the same input laser, to give strikingly sharp “sideband (SB) spectral peaks, in the backscattered spectrum. The SB intensity is a sensitive track of the polariton density and they can be detected down to a quantum noise floor that is more than 2500 times lower than the excitation thresholds of comparable quantum cascade laser diodes. Compared with other coherent scattering mechanisms, higher-order SB scattering events are readily observable, and we speculate that if suitably optimized, the effect may find utility in a passive component capable of all-optical wavelength shifting for telecommunications systems.