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arXiv · 1012.0225

Fiber-based cryogenic and time-resolved spectroscopy of PbS quantum dots

Matthew T. Rakher·Ranojoy Bose·Chee Wei Wong·Kartik Srinivasan
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Abstract

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.

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Matthew T. Rakher, Ranojoy Bose, Chee Wei Wong, Kartik Srinivasan. 2010-12-01. Fiber-based cryogenic and time-resolved spectroscopy of PbS quantum dots. https://doi.org/10.1364/oe.19.001786

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