Hu Xiaolong, Dauler Eric A, Molnar Richard J, Berggren Karl K
Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Opt Express. 2011 Jan 3;19(1):17-31. doi: 10.1364/OE.19.000017.
Optical nano-antennae have been integrated with semiconductor lasers to intensify light at the nanoscale and photodiodes to enhance photocurrent. In quantum optics, plasmonic metal structures have been used to enhance nonclassical light emission from single quantum dots. Absorption and detection of single photons from free space could also be enhanced by nanometallic antennae, but this has not previously been demonstrated. Here, we use nano-optical transmission effects in a one-dimensional gold structure, combined with optical cavity resonance, to form optical nano-antennae, which are further used to couple single photons from free space into a 80-nm-wide superconducting nanowire. This antenna-assisted coupling enables a superconducting nanowire single-photon detector with 47% device efficiency at the wavelength of 1550 nm and 9-μm-by-9-μm active area while maintaining a reset time of only 5 ns. We demonstrate nanoscale antenna-like structures to achieve exceptional efficiency and speed in single-photon detection.
光学纳米天线已与半导体激光器集成，以在纳米尺度上增强光，还与光电二极管集成以增强光电流。在量子光学中，等离子体金属结构已被用于增强单量子点的非经典光发射。纳米金属天线也可以增强对自由空间中单光子的吸收和探测，但此前尚未得到证实。在这里，我们利用一维金结构中的纳米光学传输效应，结合光学腔共振，形成光学纳米天线，进一步用于将自由空间中的单光子耦合到一根80纳米宽的超导纳米线中。这种天线辅助耦合使得超导纳米线单光子探测器在1550纳米波长、9微米×9微米有源区的情况下，器件效率达到47%，同时复位时间仅为5纳秒。我们展示了纳米级天线状结构，以在单光子探测中实现卓越的效率和速度。
