<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><!--StartFragment--><p class="MsoTitle" style="margin-right:-.5in"><span style="font-family:"Times New Roman""><b><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 13px;">Seminar
on<o:p></o:p></span></font></b></span></p><p class="MsoTitle" style="margin-right:-.5in"><span style="font-family: 'Times New Roman'; "><b><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 13px;"> </span></font></b></span><span class="Apple-style-span" style="letter-spacing: 2px; "><b><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 13px;">Modern Optics and Spectroscopy</span></font></b></span></p>
<div class="MsoNormal"><span style="font-family: Arial; letter-spacing: 1pt; "><b><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 13px;"> <o:p></o:p></span></font></b></span></div><p class="MsoBodyText" style="margin-right:-29.9pt"><span style="color: black; font-style: normal; "><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 13px;">Probing submillisecond dynamics in the
fluorescence spectra of single semiconductor nanocrystals</span></font></span></p><p class="MsoBodyText" style="margin-right:-29.9pt"><span style="color: black; font-style: normal; "><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 13px;"></span></font></span><b><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 13px;">Lisa Marshall</span></font></b><span style="letter-spacing: 1pt; "><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 13px;">,</span></font></span><span class="Apple-style-span" style="font-size: 13px; letter-spacing: 1px; ">MIT</span></p><p class="MsoBodyText" style="margin-right:-29.9pt"><span class="Apple-style-span" style="font-size: 13px; letter-spacing: 1px; "></span><span class="Apple-style-span" style="font-size: 13px; letter-spacing: 1px; ">Tuesday, March 29, 2011</span></p><p class="MsoBodyText" style="margin-right:-29.9pt"><span class="Apple-style-span" style="font-size: 13px; letter-spacing: 1px; "></span><span class="Apple-style-span" style="font-size: 13px; letter-spacing: 1px; ">12:00 – 1:00 p.m.</span></p><p class="MsoNormal" style="text-align:justify;mso-pagination:none;mso-layout-grid-align:
none;text-autospace:none"><span style="font-family:Helvetica"><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 13px;">Single-molecule
fluorescence spectroscopy is temporally limited by the need to detect enough photons to
measure a spectrum and generally reserved for chromophores isolated on a
substrate.These limitations are
particularly troubling for systems like colloidal quantum dots, where
spectral dynamics are observed on the slower time scales of conventional
camera-based measurements and assumed to be present at faster time scales as
well. Here, we use the recently developed Photon-Correlation Fourier
Spectroscopy to circumvent both of these limitations.By replacing the beam
splitter in a standard Hanbury Brown and Twiss setup with a Michelson
interferometer, we are able to compute time-dependent spectral correlations
from intensity correlations in the interference pattern from the emission of a
single chromophore. We then combine our method with Fluorescent Correlation
Spectroscopy (FCS) to extract spectral
dynamics of single chromophores freely diffusing in solution.We apply
our technique to colloidal quantum dots both at room temperature in solution and
at liquid helium temperatures and explore the spectrum of single particles on
timescales not feasible with conventional fluorescence measurements.</span></font></span></p><p class="MsoNormal" style="text-align:justify;mso-pagination:none;mso-layout-grid-align:
none;text-autospace:none"><span style="font-family:Helvetica"><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 13px;"></span></font></span><span class="Apple-style-span" style="font-size: 13px; ">Grier Room, MIT Bldg 34-401</span></p><p class="MsoNormal" style="text-align:justify;mso-pagination:none;mso-layout-grid-align:
none;text-autospace:none"><span class="Apple-style-span" style="font-size: 13px; "></span><span class="Apple-style-span" style="font-size: 13px; ">Refreshments served after the lecture</span></p><p class="MsoNormal" align="center" style="text-align:center"><o:p></o:p></p>
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