Download - 계측실험발표 Photon counting
Photon Counting20090002 Taekoo Oh
06/17/2014
06/17/2014
CONTENTS
LIGHT AS A PARTICLE
OPTICAL DEVICES
COHERENT vs. PSEUDO-THERMAL
EXPERIMENTAL SETUP
RESULTS AND DISCUSSIONS
2/18
LIGHT AS A PARTICLE
OPTICAL DEVICES
COHERENT vs. PSEUDOTHERMAL
EXPERIMENTAL SETUP
RESULTS AND DISCUSSIONS
06/17/2014
HISTORY OF LIGHT
http://commons.wikimedia.org/wiki/File:Nihal.newton_father_of_gravity.jpg
http://en.wikipedia.org/wiki/Thomas_Young_(scientist)
ISAAC NEWTON:PARTICLE
THOMAS YOUNG:WAVE
ALBERT EINSTEIN:QUANTA
http://www.brainpickings.org/index.php/tag/albert-einstein/
THE WAVE-PARTICLE DUALITY OF LIGHT!
3/18
LIGHT AS A PARTICLE
OPTICAL DEVICES
COHERENT vs. PSEUDOTHERMAL
EXPERIMENTAL SETUP
RESULTS AND DISCUSSIONS
06/17/2014
LIGHT AS A PARTICLE
-
PHOTOELECTRICEFFECT
-𝜆
𝜆′
COMPTONSCATTERING
4/18
LIGHT AS A PARTICLE
OPTICAL DEVICES
COHERENT vs. PSEUDOTHERMAL
EXPERIMENTAL SETUP
RESULTS AND DISCUSSIONS
06/17/2014
PHOTON STATISTICS
SUPER-POISSONIAN(BUNCHED)
POISSONIAN(COHERENT)
SUB-POISSONIAN(ANTI-BUNCHED)
Δ𝑛 = 𝑛
Δ𝑛 < 𝑛
Δ𝑛 > 𝑛
5/18
Mark Fox, in Quantum Optics: An introduction, Chapter 6.
𝑔 2 0 > 1
𝑔 2 0 = 1
𝑔 2 0 < 1
Fluctuation of the number of photon in very short time
interval?
LIGHT AS A PARTICLE
OPTICAL DEVICES
COHERENT vs. PSEUDOTHERMAL
EXPERIMENTAL SETUP
RESULTS AND DISCUSSIONS
06/17/2014
OPTICAL DEVICES
He-Ne Laser
“Light Amplified by Stimulated Emission of Radiation”
𝜆 = 632.8 𝑛𝑚
He
Ne
Excitation by Electric Discharge
Collision
Collision to wall
Spontaneous Emission
6/18
LIGHT AS A PARTICLE
OPTICAL DEVICES
COHERENT vs. PSEUDOTHERMAL
EXPERIMENTAL SETUP
RESULTS AND DISCUSSIONS
06/17/2014
OPTICAL DEVICES
Single Photon Counting Module (SPCM)
http://en.wikipedia.org/wiki/Avalanche_photodiode#mediaviewer/File:Avalanche_photodiode.JPG
At 22𝑜𝐶,
Avalanche Photodiode
Dark Count(c/s) 1500
Dead time(ns) 20(T) / 40(M)
Single PhotonTiming Resol.(ps)
350 at 825nm
OperatingTemperature
5 to 70𝑜𝐶
7/18
LIGHT AS A PARTICLE
OPTICAL DEVICES
COHERENT vs. PSEUDOTHERMAL
EXPERIMENTAL SETUP
RESULTS AND DISCUSSIONS
06/17/2014
COHERENT LIGHT
𝑝 𝑛 = 𝑛𝑒− 𝑛
𝑛!
In the State of temporally and spatially stationary interference!
If we consider the statistics of themonochromatic coherent light,
Poisson Distribution
POISSONIAN LIGHT!
8/18
LIGHT AS A PARTICLE
OPTICAL DEVICES
COHERENT vs. PSEUDOTHERMAL
EXPERIMENTAL SETUP
RESULTS AND DISCUSSIONS
06/17/2014
THERMAL LIGHT
𝑝 𝑛 = 𝑛𝑛
( 𝑛 + 1)𝑛+1
At a certain temperature T, an object radiatesthermal light!
Bose-Einstein Distribution
If we consider the statistics of themonochromatic thermal light,
𝜌 𝜔, 𝑇 =2ℎ𝜔3
𝑐21
𝑒 ℎ𝜔𝑘𝑇 − 1
SUPER-POISSONIAN LIGHT!
(∆𝒏)𝟐= 𝒏 + 𝒏𝟐
𝑵𝒎
9/18
LIGHT AS A PARTICLE
OPTICAL DEVICES
COHERENT vs. PSEUDOTHERMAL
EXPERIMENTAL SETUP
RESULTS AND DISCUSSIONS
06/17/2014
PSEUDO-THERMAL LIGHTRotating Ground Disk
Monochromatic Coherent Light
Randomly DistributedPhoton
Monochromatic Pseudo-thermal Light
Partially Bunched,But in long period,
Randomly DistributedPhoton
That is, the light behaves as thermal light in coherence time!
glass
𝝉~𝟏𝟎−𝟓 𝒕𝒐 𝟏 𝒔𝒆𝒄, 𝝉 ⋉𝟏
𝒗
10/18
LIGHT AS A PARTICLE
OPTICAL DEVICES
COHERENT vs. PSEUDOTHERMAL
EXPERIMENTAL SETUP
RESULTS AND DISCUSSIONS
06/17/2014
EXPERIMENTAL SETUP
He-NeLaser
For Coherent Light
For Pseudo-Thermal Light
Rotating Ground Disk
Polarizers
Single Photon
Counting Module
NI ELVIS
11/18
LIGHT AS A PARTICLE
OPTICAL DEVICES
COHERENT vs. PSEUDOTHERMAL
EXPERIMENTAL SETUP
RESULTS AND DISCUSSIONS
06/17/2014
RESULTS
Photon Number Distribution in coherent light at 0.1ms cutoff time
0
0.05
0.1
0.15
0.2
0.25
0 10 20 30 40
Pro
bability
Photon Number
Experimental Value
Theoretical Value
12/18
Average : 3.53
LIGHT AS A PARTICLE
OPTICAL DEVICES
COHERENT vs. PSEUDOTHERMAL
EXPERIMENTAL SETUP
RESULTS AND DISCUSSIONS
06/17/2014
RESULTS
0
0.02
0.04
0.06
0.08
0.1
0.12
0 10 20 30 40 50 60
Pro
bability
Photon Number
Experimental Value
Theoretical Value
Photon Number Distribution in pseudo-thermal light at 0.1ms cutoff time
13/18
Average : 8.91
LIGHT AS A PARTICLE
OPTICAL DEVICES
COHERENT vs. PSEUDOTHERMAL
EXPERIMENTAL SETUP
RESULTS AND DISCUSSIONS
06/17/2014
RESULTS
0
0.05
0.1
0.15
0.2
0.25
0 10 20 30 40 50 60
Pro
bability
Photon Number
0.1ms_Theory
0.2ms_Theory
0.3ms_Theory
0.4ms_Theory
0.1ms_Experiment
0.2ms_Experiment
0.3ms_Experiment
0.4ms_Experiment
Average : 26.22
Photon Number Distribution in pseudo-thermal light at 0.1ms cutoff time
14/18
Average : 3.53
Average : 16.67
Average : 40.10
LIGHT AS A PARTICLE
OPTICAL DEVICES
COHERENT vs. PSEUDOTHERMAL
EXPERIMENTAL SETUP
RESULTS AND DISCUSSIONS
06/17/2014
RESULTS
Photon Number Distribution in pseudo-thermal light from 0.01ms to 0.05ms cutoff time
15/18
0
0.02
0.04
0.06
0.08
0.1
0.12
0 5 10 15 20 25 30 35 40
Pro
bability
Photon Number
0.01ms Cutoff Time
0.02ms Cutoff Time
0.03ms Cutoff Time
0.04ms Cutoff Time
0.05ms Cutoff Time
Average : 8.91
Average : 13.84
Average : 18.14
Average : 24.02
Average : 28.05
LIGHT AS A PARTICLE
OPTICAL DEVICES
COHERENT vs. PSEUDOTHERMAL
EXPERIMENTAL SETUP
RESULTS AND DISCUSSIONS
06/17/2014
RESULTS
Photon Number Distribution in pseudo-thermal light with shorter coherence timefrom 0.01ms to 0.05ms cutoff time
16/18
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0 5 10 15 20 25 30 35 40
Pro
bability
Photon Number
0.01ms_Experiment
0.01ms_Theory
0.02ms_Experiment
0.02ms_Theory
0.03ms_Experiment
0.03ms_Theory
0.04ms_Experiment
0.04ms_Theory
0.05ms_Experiment
0.05ms_Theory
Average : 7.19
Average : 13.33
Average : 22.02
Average : 26.27
Average : 30.69
LIGHT AS A PARTICLE
OPTICAL DEVICES
COHERENT vs. PSEUDOTHERMAL
EXPERIMENTAL SETUP
RESULTS AND DISCUSSIONS
• The fluctuation of the photon number in the short time period is due to the quantum properties of the light.
• The statistics of the photon number of coherent light is Poisson distribution, without the relevance of the cutoff time.(Poissonian light)
• The statistics of the photon number of thermal light is Bose-Einstein distribution.(Super-Poissonian light)
• Pseudo-thermal light behaves as thermal light only in the case of the cutoff time within the coherence time.
06/17/2014
RECAPITULATION
17/18
06/17/2014
REFERENCE- Mark Fox, in Quantum Optics: An introduction (Oxford
University Press, 2006), Chap. 5.- Rodney Loudon, in The Quantum Theory of Light
(Oxford University Press, 2000), Chap. 5.- Li Yuan et al., CHIN. PHYS. LETT., 26, 7 (2009).- G. J. Troup, J. Lyons, PHYS. LETT. A, 29, 11 (1969).- M. Rousseau, J. Opt. Soc. Am., 61, 10 (1971).- T. Gonsiorowski, J. C. Dainty, J. Opt. Soc. Am., 73, 2
(1983).- Jed Rembold, in Statistical Mechanics (New Mexico
Tech, 2011). - W. Martienssen, E. Spiller, Am. J. Phys. 32, 919 (1964).- F. T. Arecchi, PHYS. REV. LETT., 15, 912 (1965).
18/18
THANK YOU!
06/17/2014