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Chemistry on Ultrafast and Ultrasmall Scales
Trevor SmithKen GhigginoPaul Mulvaney
School of Chemistry,University of Melbourne
Ultrasmall - techniques
Confocal and multiphoton microscopy
Single molecule detection and emission spectroscopy FCS, antibunching Polymers & quantum dots
Total internal reflection fluorescence (EWIF)
Ultrasmall - facilities
Scanning confocal and multiphoton microscopy Time-resolved fluorescence imaging
LaVision PicoStar TCSPC (EI, Becker & Hickl, other)
Single molecule detection and emission spectroscopy
FCS, antibunching, single molecule spectroscopy (spectrograph/CCD)
Polymers & quantum dots Total internal reflection fluorescence (EWIF) Scanning near field (SNOM)
Ultrafast - techniques
Time-correlated single photon counting Time-resolved fluorescence anisotropy
Flash photolysis Pump-probe techniques
Time-resolved absorption Fluorescence upconversion Multi-pulse, multi-wavelength photon
echoe
Ultrafast - facilities
Nanosecond flash photolysis (Nd:YAG/OPO) ns gated CCD/spectrometer
Picosecond dye lasers Femtosecond Ti:sapphire systems
oscillator/OPO system Pulse picked/cavity dumped MHz rep. rates, nJ pulse energies, tuneable
amplified femtosecond Ti:sapphire oscillator/OPA <280 kHz rep. rates, µJ-10s of nJ pulse energies,
tuneable
Evanescent Waves
n1
n2
n1> n2
Standing wave
Total internal reflection(if i> c)
Evanescent waveE=Eoexp(-x/)
Refraction(if i< c)
IncidentBeam, Eo
Interface
Normal
i
EWIF spectroscopy EWIF-FCS Time-resolved EWIFS Time-resolved EWIF anisotropy Time-resolved EWIF microscopy
Expressions for polarisations perpendicular, s, & parallel, p, to plane of incidence:
In bulk solution:
In-plane:
Out-of-plane:
r t Izy t 1
2Iyy t Iyx t
Izy t Iyy t Iyx t
r t Iyy t Iyx t Iyy t Iyx t
rbulk Iyy (t) Iyx (t)Iyy (t) 2Iyx (t)
Polarised EWIF
z
x
y
TREWIF Anisotropy
0 10 20 30 40 50 60 70Time (ns)
BULK
= 64 nm
= 76 nm
= 113 nm
INCREASINGDISTANCE AWAY FROMINTERFACE
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
r(t)
N
H
S
O
3
H
“In-plane” and “Out-of-Plane” anisotropy
-0.1
-0.05
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0 20 40 60 80 100 120
Time (ns)
r(t)
Bulk900nm353nm260nm215nm188nm155nm135nm120nm
N
N
N
H
+
-0.1
-0.05
0
0.05
0.1
0.15
0.2
0 20 40 60 80 100 120Time (ns)
r(t)
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