Transcript Quantum Optics Team A: “Mach-Zehnder Interferometer and

By: Nicholas Cirucci, Rebecca Pettenski, Christina Loniewski, Timothy
Geary, Nathan Damon

To show wave-particle duality of photons
Quantum: A Guide for the Perplexed, by Jim Al-Khalili

“Interference phenomena are viewed as the
most convincing ‘proof’ of the wave nature of
light”

Introduction to Quantum Optics from Light Quanta to Quantum Teleportation, By Harry
Paul


At the single photon level, will the photon
exhibit wave-particle duality?
Quick overview of experiments
Costs $30,000
8.2 x 8.2 mm image area
Internally regulated temperature at -60 degrees
Celsius
 Camera has single-photon detection capability
 Andor iXon DV887 mode
 EMCCD Camera (Electron Multiplying Charge
Coupling Device)




http://www.optics.rochester.edu/workgroups/lukishova/QuantumOpticsLab/homepage/andor_em_ccd_
camera.pdf




HeNe Gas laser
633 nm wavelength (red)
No anti-bunching exhibited by this laser
Only single, double, and triple photon
“groups”
Unpolarizing
Beam Splitter
Mirror
Linear Polarizer
Circular Aperture
45 Degree
Linear Polarizer
Mirror
Polarizing
Beam Splitter

“The process of splitting becomes conceptually
difficult when we think of the beam as consisting of
spatially localized energy packets, or photons…what
happens to the individual photon when it hits the
mirror? Does it split, or does it remain as a whole?”
 Introduction to Quantum Optics from Light Quanta to Quantum Teleportation,
By Harry Paul
Beam splitter


At 45 degrees, photon does not know s or p
polarization, so there are interference fringes
The 45 degree linear polarizer ensures that
there is an equal probability that the photon
will travel down one arm or the other

Quantum mechanical properties are completely
dependent upon how they are observed. You
cannot accurately measure both the particle and
wave properties of light.

Quantum Physics: Illusion or Reality?, Alastair I. M. Rae

Energy of Photon
 Wavelength = 633nm

Order of Attenuation


Laser power = 53.9 uW
Laser Power—measuring power to make sure both arms of
interferometer are the same power—more likely for photon
to go where there is more power (if unequal)

“What happens to the ability of the waves to
interfere at very low intensities? Do laser
beams interfere after they are strongly
attenuated?” (i.e. on the single photon level)
 Introduction to Quantum Optics from Light Quanta to Quantum Teleportation,
By Harry Paul
Quantum: A Guide for the Perplexed, by Jim Al-Khalili
Quantum: A Guide for the Perplexed, by Jim Al-Khalili



Changing Polarizer Angles
Accumulations
Sample picture of Mach-Zehnder
Interference Fringes:


V=(Imax-Imin)/(Imax+Imin)
Example of Fringe Intensity Pattern:
(Fringe Visibility) V= 0.658517
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
210
220
230
240
250
260
270
280
290
300
310
320
330
340
350
360
.4
.2
0
Fringe Visibility
.6
.8
Fringe Visibility vs. Changing Polarizer Angles
45
90
135
180
225
Polarizer Angles (degrees)
270
315
360
1
6
2
7
3
8
4
9
5
10
45 Degree Polarizer Angle: Fringe Visibility vs. Increasing
Accumulations on the Single Photon Level—Exposure
Time .005 Seconds
7 Orders of Attenuation
.6
0.7
0.6
.4
0.4
.2
0.3
0.2
0.1
0
Fringe Visibility
0.5
0
1
1
2
3
3
4
5
5
Accumulations
6
7
7
8
9
9
10







Familiarized with equipment
Which-way theory
Can only prove wave-particle duality at the
single photon level
Energy of a photon
Attenuation Calculation
Using the Andor program in conjunction with
the Andor camera
Aligned the Mach-Zehnder Interferometer
90 um between slits
10 um
width
of slit

“My theory of light and colours, though it did
not occupy a large portion of my time, I
conceived to be of more importance than all
that I have ever done, or ever shall do besides.”
~Thomas Young

Quantum: A Guide for the Perplexed, by Jim Al-Khalili
Quantum: A Guide for the Perplexed, by Jim Al-Khalili


Explanation
Schematics
 http://www.edmundoptics.com/technical-support/lasers/understanding-
spatial-filters/
Dirty
Profile
Clean
Profile
Lens 2
Lens 1
Laser Beam
Pinhole
Magnified
Beam
11
2
3
4
5
6
7
8
9
10
12
13
14
15
16
17
18
19
20
Fringe Visibility vs. Increasing Accumulations on
the Single Photon Level—Exposure Time of .05
7 Orders of Attenuation
Seconds
0.3
0.25
Fringe Visibility
0.2
0.15
0.1
0.05
0
2
3
4
5
6
7
8
9
10
11
12
Accumulations
13
14
15
16
17
18
19
20


Learned much more about interference
fringes
Interference affected by multiple sources



.
Attempting to detect photons after they pass
through the slit with a slight delay on the
detector
After the photon goes through the slit, the
detector records which slit it went through
after a short period of time
If this occurs, then the interference patterns
disappear
Quantum: A Guide for the Perplexed, by Jim Al-Khalili
Introduction to Quantum Optics from Light Quanta to Quantum
Teleportation, By Harry Paul







Calculated 8 orders of attenuation
Dust on attenuation filters
Misaligned beams
Camera noise
Software difficulties
Dirty Mirrors and/or beam splitters
Flea in Camera

Attenuation Filter
 $80

Andor EMCCD Camera
 $30,000

Learning about Quantum Optics
 Priceless
1. http://www.optics.rochester.edu/workgroups/lukishova/QuantumOpticsLab
/homepage/andor_em_ccd_camera.pdf
2. http://www.edmundoptics.com/technical-support/lasers/understandingspatial-filters/
3. Quantum: A Guide for the Perplexed, by Jim Al-Khalili
4. Introduction to Quantum Optics from Light Quanta to Quantum
Teleportation, By Harry Paul
5. Quantum Physics: Illusion or Reality?, Alastair I. M. Rae