Dr Dirk Bezuidenhout

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Transcript Dr Dirk Bezuidenhout

Project PRISM
Optronics: Protection &
Surveillance
Dr Dirk Bezuidenhout
CSIR
Universities Involved
Stellenbosch
Physics (Dr E Rohwer)
Process Eng (Prof H Knoetze)
NMMU
Physics (Prof J Engelbrecht)
Rhodes
Chemistry (Prof T Nyokong)
UKZN
Computer Science (Prof J-R Tapamo)
Physics (Dr V Couling)
Universities Involved
UJ
Electr. & Electronic Eng. (Dr W Clarke)
UP
Mathematics (Dr R Anguelov)
TUT
French South African Technical Institute in Electronics
(Prof B van Wyk)
Number of Students
Nine Departments
Eight Disciplines
Number of Students: 22
PRISM-L: Lasers
Light Sources
Countermeasures
Beam Propagation
High-power end-pumped Nd:YLF
OC
AOM
R = - 30 mm
L1
Pump diode 1
R = 150 mm
Nd:YLF
Pump diode 2
Reverse Saturable Absorption
Fibre Laser Laboratory
PRISM-P: Pyrophorics
Pyrophorics
Interface with Project COUPLE
PRISM-M
Layout: Missile optics
Semi- conductor Materials
4.0
G aN
ZnO
400
Energy G ap (eV)
3.0
SiC
2.5
GaP AlAs
600
2.0
AlSb
1.5
1.0
GaAs
Si
CdTe
800
InP
1000
GaSb
0.5
InAs
0.0
0.30 0.32 0.34
2000
InSb
HgTe
0.52 0.54 0.56 0.58 0.60 0.62 0.64 0.66 0.68
Lattice constant (nm)
W avelength (nm )
3.5
Bandgap Modification
3000
3.537 μm
0.35
4000
4.218 μm
0.25
0.15
0.0 0.089 0.2
InAs
5000
6000
2K
8000
10000
300 K
15000
0.4
0.6
Sb mole fraction x
0.8
1.0
InSb
Bandgap spans strategic 3-7 μm range at low T
Wavelength [nm]
0.45
Lattice-matched
to GaSb
Bandgap Energy [eV]
InAs1-XSbX
Backside Illumination
Development of InAs0.91Sb0.09/GaSb backsideilluminated detector
λcut-off ~3.6 μm at 77 K
p:InAsSb
n:InAs
n:GaSb Substrate
Optical Limiters: Electronic structure
2 photon absorption
Singlet states S, triplets T
Cross sections σ
Inter-System Crossing
Desirable properties:
high triplet quantum yield
σex >> σg
rapid inter-system crossing
a long lifetime τT in the triplet state
optical stability
High damage thresholds for the
material
Metallo-phthalocyanines, MPc
Axial substituent
Peripheral substituent
Unsubstituted MPc
Substituted MPc
Symmetry
ZnPc
0.35
C2v dome shape is energy minimum
0.3
0.25
C2v
0.2
z /Å
0.15
0.1
0.05
0
0
1
2
3
4
-0.05
-0.1
-0.15
r /Å
5
6
7
8
Highest Occupied Molecular Orbital
Results
Vibrational frequencies
Frequency
1800
1600
1400
1200
1000
800
600
400
0
IR intensity
1
2
3
4
5
6
Image Processing
Optical Surveillance Path
Solar Glint
Discreet Pulse Transforms
Develop a method for the decomposition of images into
2D block pulses
Analysis of sea images via discrete pulse decomposition
Characterization of the images of marine background in
varying conditions
Developing algorithms for identifying anomalies in a sea
image
Algorithms for target detection using the discrete pulse
decomposition of the image
Image Processing and Optical Tracking
Optical Tracking
Image Processing
Solving the Heat Scintillation
Problem in Images
(Rishaad Abdoola)
Robust Real-Time Motion Detection
(Petrus Nyathela)
Gated Camera Applications
Stress Induced Birefringence
Birefringence Map for doublet
Questions