Rakher Matthew T, Bose Ranojoy, Wong Chee Wei, Srinivasan Kartik
Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6203, USA.
Opt Express. 2011 Jan 31;19(3):1786-93. doi: 10.1364/OE.19.001786.
PbS quantum dots are promising active emitters for use with high-quality Si nanophotonic devices in the telecommunications-band. Measurements of low quantum dot densities are limited both because of low fluorescence levels and the challenges of single photon detection at these wavelengths. Here, we report on methods using a fiber taper waveguide to efficiently extract PbS quantum dot photoluminescence. Temperature dependent ensemble measurements reveal an increase in emitted photons concomitant with an increase in excited-state lifetime from 58.9 ns at 293 K to 657 ns at 40 K. Measurements are also performed on quantum dots on high-Q (>10(5)) microdisks using cavity-resonant, pulsed excitation.
硫化铅量子点有望成为与电信波段高质量硅纳米光子器件配合使用的有源发光体。低量子点密度的测量受到限制，这既是因为荧光水平较低，也是因为在这些波长下进行单光子检测存在挑战。在此，我们报告了使用光纤锥形波导有效提取硫化铅量子点光致发光的方法。与温度相关的系综测量表明，发射光子数量增加，同时激发态寿命从293 K时的58.9纳秒增加到40 K时的657纳秒。我们还使用腔共振脉冲激发对高Q值（>10⁵）微盘上的量子点进行了测量。
