lecture 4 February 2013 Kai Wicker Exam written exam 26 February 2013 exact time and place will be announced by email Today The quantum world in microscopy 1 Photon antibunching 2 ID: 231318
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Slide1
Advanced Optical Microscopy
lecture
4. February 2013
Kai WickerSlide2
Exam:
written exam
26 February 2013
exact time and place will be announced by emailSlide3
Today:
The quantum world in microscopy
1.
Photon anti-bunching
2.
Interaction-free measurements
3
.
Entangled photons, parametric down-conversion
4.
Beating shot-noise
5.
Entangled two-photon microscopySlide4
1. Photon anti-bunchingSlide5
Jablonski
diagram
Absorption…
… and spontaneous emission
Normal fluorescenceSlide6
Photon anti-bunching:
- only 1 photon per emitter and excitation pulse
- sub-
Poissonian
(!) statistics
1.0
anti-bunchingSlide7
Possible applications of p
hoton anti-bunching:
- single molecule localisation: is it really just one single molecule?
- super resolution imaging exploiting sub-
Poissonian statisticsSlide8
Super
resolution imaging exploiting sub-
Poissonian
statistics
a) Pulsed excitation and synchronised detectionb) + d) Two-pixel correlationsc) + e) Three-pixel correlationsSlide9
Super
resolution imaging exploiting sub-
Poissonian
statistics
a) + d) Conventional fluorescence imageb) + e) Second order anti-bunchingc) + f) Third order anti-bunchingSlide10
2.
Interaction-free measurements
Seeing without lightSlide11
Mirror
Transmitted light
Reflected light
Fabry
-Perot resonatorSlide12
Reflected light
Transmitted light
Transmitted light
Reflected light
Transmitted light
Mirror
Fabry
-Perot resonatorSlide13
Mirror
Fabry
-Perot resonatorSlide14
opposite phase
cancellation
Mirror
Fabry
-Perot resonatorSlide15
Case 1
One
mirror
Case 2
Two
mirrors
,
resonator
Case 3
Two
mirrors
with
obstacle
Fabry
-Perot resonator
Interaction-
free
measurementSlide16
Experiment:
Imaging
photographic
film
without
exposing
it
to
light
„sample“-film
„
detector
“-film
scan
areaSlide17
Experiment:
Imaging
photographic
film
without exposing it to lightSlide18
3.
Entangled photons, parametric
down-conversionSlide19
Coherent
super
-positions of states:
“click”Slide20
Image: European
Space
Agency
parametric down-conversion
Position entanglement!Slide21
4.
Beating shot-noiseSlide22
Beating shot-noise
Position entanglement!
Image: Alessandra
Gatti
, Enrico
Brambilla
, and Luigi
Lugiato
, “Quantum Imaging,” 2007
Intensity distributions are correlated, even down to Poisson noise!!Slide23
Identical
!
Quantum image:
Weakly absorbing object
Illumination
Not correlated!
Classical image:
Beating shot-noiseSlide24
Beating shot-noise
imaging a weakly absorbing objectSlide25
Beating shot-noise
imaging a weakly absorbing object
Simulation
Sample
Classical image: SNR 1.2
Quantum image: SNR 3.3Slide26
Beating shot-noise
imaging a weakly absorbing object
Experiment
Sample:
π-shaped titanium deposition
Classical image: SNR 1.2
Quantum image: SNR 1.7Slide27
5.
Entangled two-photon microscopySlide28
Jablonski
diagram
NO absorption…
Normal
fluorescenceSlide29
Jablonski
diagram
2-photon a
bsorption
…
… and spontaneous emission
2-photon
fluorescenceSlide30
2-photon
fluorescence
Classical
:
2-photon absorption requires
two photons to be present simultaneously.
The probability for this grows
quadratically
with intensity.
It will only occur where the local intensity is high.
Quantum:
2-photon absorption requires
two photons to be present simultaneously.
This
is
achieved
through
temporal
coincidence
of
entangled
photons
.Slide31
Entangled two-photon
microscopy
Comparisson
of different imaging modalities:Slide32
Entangled two-photon microscopySlide33
End of lecture