february 2006chuck dimarzio, northeastern university10842-2-1 eceg398 quantum optics course notes...
TRANSCRIPT
February 2006 Chuck DiMarzio, Northeastern University 10842-2-1
ECEG398 Quantum Optics Course Notes
Part 2: Thermal Imagers
Prof. Charles A. DiMarzio
and Prof. Anthony J. Devaney
Northeastern University
Spring 2006
February 2006 Chuck DiMarzio, Northeastern University 10842-2-2
Thermal Fields
• Mean Number (Text Eq.2.141):
• Std. Deviation (Text Eq. 2.149):
• Energy Density (Text Eq. 2.151):
1
1/
Tkh Ben
2nn
1
14/3
3
Tkh Bec
hnhU
February 2006 Chuck DiMarzio, Northeastern University 10842-2-3
Single-Mode Mean
100 200 500 1000 2000 5000 10000lambda , Wavelength , nm1. 1032
1. 1026
1. 1020
1. 1014
1. 108
0.01
nbar :Red Solid : T300 K,Grn Dash : 5000 K
February 2006 Chuck DiMarzio, Northeastern University 10842-2-4
100 500 1000 5000 10000 50000100000.lambda , Wavelength , nm
0.00001
0.001
0.1
SNR :Red Solid : T300 K,Grn Dash : 5000 K
Single Mode SNR
Upper Trace is Poisson
0.1mm
February 2006 Chuck DiMarzio, Northeastern University 10842-2-5
Spectral Radiant Exitance
Watch the Units:
Md
dM
d
dMM 22
M
c
d
dMc
d
dM
d
d
d
dMM
22
U
cnhM
February 2006 Chuck DiMarzio, Northeastern University 10842-2-6
Signal & Noise Radiant Exitance
100 200 500 1000 2000 5000 10000lambda , Wavelength , nm0.01
10
10000
1. 107
1. 1010
1. 1013
Spect . Rad . Ex., Wm^3:Red Solid : T300 K,Grn Dash : 5000 K
cnhM
cnnhM noise2
)(
February 2006 Chuck DiMarzio, Northeastern University 10842-2-7
Lambert’s Law
A
A’
February 2006 Chuck DiMarzio, Northeastern University 10842-2-8
Spectral Radiance
x
y
z
d
d
February 2006 Chuck DiMarzio, Northeastern University 10842-2-9
Black-Body Equation (1)
10-1
100
101
102
10-10
10-5
100
105
1010
, Wavelength, m
M,
Sp
ectr
al
Ra
dia
nt
Exi
tan
ce,
W/m
2/
m
February 2006 Chuck DiMarzio, Northeastern University 10842-2-10
Black Body Equations (2)
10-1
100
101
10210
-10
10-5
100
105
1010
, Wavelength, m
M,
Spe
ctra
l Rad
ian
t Exi
tan
ce, W
/m2 /
m
T=300k
500
1000
2000
5000
10000
February 2006 Chuck DiMarzio, Northeastern University 10842-2-11
Solar Irradiance on Earth
0 200 400 600 800 1000 1200 1400 1600 1800 20000
500
1000
1500
2000
2500
3000Data from The Science of Color, Crowell, 1953
, Wavelength, nm
E
, S
pe
ctra
l Irr
ad
ian
ce,
W/m
2/
m
Exoatmospheric filename=m1695.mSea Level
5000 K Black Body Normalized to 1000 W/m2
6000 K Black Body Normalized to 1560 W/m2
February 2006 Chuck DiMarzio, Northeastern University 10842-2-12
Typical Outdoor Radiance Levels
VisibleNear IR
Mid IRFar IR
Atmospheric Passbands
Ultraviolet6000K Sun6.9 G Lux
SunlitCloud6.9 k Lux
BlueSky 300K
night sky
February 2006 Chuck DiMarzio, Northeastern University 10842-2-13
Thermal Imaging
M
/Del
ta T
10-1
100
101
1020
.5
1
T = 300 K
10-1
100
101
1020
2
4
6
, Wavelength, m
M
/D
elta
TT = 500 K
February 2006 Chuck DiMarzio, Northeastern University 10842-2-14
Etendue
Viewedby Pixel
PixelArea
NA of Detector Lens
NA ofObjective
Area of PRC
NA ofPRC
A isConstant
2112 NA
2NA
Single Mode
dNA /2A
A
dAdLP
February 2006 Chuck DiMarzio, Northeastern University 10842-2-15
Spectral Flux (Power) Per Mode
100 200 500 1000 2000 5000 10000lambda , Wavelength , nm1. 1015
1. 1012
1. 109
1. 106
0.001
1
Pl, Wmmode :Red Solid : T300 K,Grn Dash : 5000 K
February 2006 Chuck DiMarzio, Northeastern University 10842-2-16
Probability DistributionsLaserMode
ThermalMode
ManyThermalModes
Re(E) Im(E) |E| |E|2 n
(Delta) (Delta) (Poisson)
(Gaussian) (Rayleigh) (Exponential)
(Bose-Einstein)
(Poisson)SummedonDetector
February 2006 Chuck DiMarzio, Northeastern University 10842-2-17
Detected Photons (Signal & Bkg)
B
Acnn qDet
1
Ps
PBKG
BPF
Preamp AmpFilter
PNoise
q
February 2006 Chuck DiMarzio, Northeastern University 10842-2-18
Detector Examples: Spectral Photon Radiance
10464-3-32
February 2006 Chuck DiMarzio, Northeastern University 10842-2-19
Detector Examples: Total Background Power
10464-3-31
February 2006 Chuck DiMarzio, Northeastern University 10842-2-20
Noise Photons (Bkg. Limited)
B
Acnq
1
B
Acnn qDet
1
February 2006 Chuck DiMarzio, Northeastern University 10842-2-21
Noise-Equivalent Power
Bh
LA
Bh
Pn qqDet
Bh
LAq
Bh
NEPq
q
LABh
Bh
LABhNEP
1
February 2006 Chuck DiMarzio, Northeastern University 10842-2-22
Detector Examples: NEP
10464-3-3
February 2006 Chuck DiMarzio, Northeastern University 10842-2-23
D-Star
ABLhLABhNEP
LhD q
*
max *D
ABNEP
February 2006 Chuck DiMarzio, Northeastern University 10842-2-24
Detector Examples: Detectivity, D*
10464-3-34
February 2006 Chuck DiMarzio, Northeastern University 10842-2-25
Estimating the Temperature
B
Acnn qDet
1
1
1/
Tkh Ben
Ce
Tkh
e
dT
ndTkh
B
Tkh
B
B
2/
2/
1
TB
ACcn qDet
1
February 2006 Chuck DiMarzio, Northeastern University 10842-2-26
Noise-Equivalent Delta T
B
Acnq
1
TB
ACcn qDet
1
TNEB
ACcq
1
February 2006 Chuck DiMarzio, Northeastern University 10842-2-27
Calculating NET
TNEB
ACc
B
Acn qq
11
C
n
cA
BTNE
q
T=300Kelvin, q=0.8, B=30 Hz, =1m, A=(10mm)2, =0.1 sr
7 X 106 Photons/Kelvin NET=5 mKelvin