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Register a new userSpectroscopy of 1.55 $mu$m PbS Quantum Dots on Si Photonic Crystal Cavities with a Fiber Taper Waveguide
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We use an optical fiber taper waveguide to probe PbS quantum dots (QDs) dried on Si photonic crystal cavities near 1.55 $mu$m. We demonstrate that a low density ($lesssim 100 mu$m$^{-2}$) of QDs does not significantly degrade cavity quality factors as high as $approx3times10^4$. We also show that the tapered fiber can be used to excite the QDs and collect the subsequent cavity-filtered photoluminescence, and present measurements of reversible photodarkening and QD saturation. This method represents an important step towards spectroscopy of single colloidal QDs in the telecommunications band.
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