1. ECE-1466 Modern Optics Course Notes Part 5
Prof. Charles A. DiMarzio
Northeastern University
Spring 2002
Mayl 02002
Chuck DiMarzio, Northeastern University

2. Basic Equations of Interference
Im E
Re E
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Chuck DiMarzio, Northeastern University

3. Chuck DiMarzio, Northeastern University
Mach Zehnder (1)
Example M2
BS1
Source, s
Gas Cell
n>1 M1
BS2
Straight-Line Layouts:
Transit Time s
BS1 M1
BS2 s
BS1 M2
BS2
Geometric s
BS1 M1
BS2 s
BS1 M2
BS2
Mayl 02002
Chuck DiMarzio, Northeastern University

4. Chuck DiMarzio, Northeastern University
Mach Zehnder (2)
Straight-Line Layout: Transit Time s
BS1 M1
BS2 s
BS1 M2
BS2 q
Diffuser
Mayl 02002
Chuck DiMarzio, Northeastern University

5. Chuck DiMarzio, Northeastern University
Optical Testing
M1, Known Reference
Spheres 4-wave difference
Same with 2-wave bump
-50 50
0.5 1
1.5 2
-50 50
0.5 1
1.5 BS
M2,
Mirror Under Test
Flats with 8-wave tilt
Same with 2-wave bump
-50 50
0.5 1
1.5 2
-50 50
0.5 1
1.5 2
Mayl 02002
Chuck DiMarzio, Northeastern University

6. Fabry-Perot Interferometer (1)
Straight Line Model
Multiple Sources, with decreasing amplitudes (usually) and increasing distances (and thus phases).
Mayl 02002
Chuck DiMarzio, Northeastern University

7. Fabry-Perot Interferometer (2)
10mm
650nm
600nm
460
470
480
490
500
0.05
0.1
0.15
0.2
0.25
f, Freq., THz
T, Transmission
FSR
d f
Mayl 02002
Chuck DiMarzio, Northeastern University

8. Chuck DiMarzio, Northeastern University
Laser Tuning (1)
Gain Lines
Depend on Medium
Often Multiple
10’s to 100’s of THz.
Cavity Modes
qc/2L
q is an inteter
L is cavity length
Free Spectral Range
c/2L (Mode Spacing)
Gain f
Cavity Modes f
Mayl 02002
Chuck DiMarzio, Northeastern University

9. Chuck DiMarzio, Northeastern University
Laser Tuning (2)
Fine Tuning
Cavity Length
Usually Piezoelectric
Intracavity Modulator
Single Mode
Intracavity Etalon or
Short Cavity
Single Gain Line
Prism or Grating
Gain f
Cavity Modes f qi
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Chuck DiMarzio, Northeastern University

10. Chuck DiMarzio, Northeastern University
Etalon Transmission
Only Coherent Sources
contribute to the fringes
Im (1/t)
Re (1/ t)
Mayl 02002
Chuck DiMarzio, Northeastern University

11. Thin Films: Three Approaches
Sum the multiple
Reflections
Use Wave Equation
and Boundary
Conditions
Network Approach
with Fresnel Coefficients EA EB EC ED E1 E2 E3 E4
E’1
E’2
E’3
E’4
Mayl 02002
Chuck DiMarzio, Northeastern University

12. Chuck DiMarzio, Northeastern University
Thin Film Matrices (2) M1 M4
M=M1M2M3M4
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Chuck DiMarzio, Northeastern University

13. High Reflection Stack (1)
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Chuck DiMarzio, Northeastern University

14. High Reflection Stack (2)
Phase=0
p+p
2p+0
3p+p
Sign of Reflectivity is inverted
on going from High to Low
Index.
Mayl 02002
Chuck DiMarzio, Northeastern University

15. Anti-Reflection Coatings
Examples R
Uncoated Glass 4%
Two
Layers
One
Layer
Phase =0 p
Three
Layers
Quarter-Wave Coating
Magnesium Flouride n=1.35
is a close match, low cost and durable. l
Violet
Red
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Chuck DiMarzio, Northeastern University

16. Interference Magnitudes
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Chuck DiMarzio, Northeastern University

17. Quadrature Imaging Concept
Balanced Mixing
November 18

18. Quadrature Images from Original Setup
One-Cell Embryo
Two-Cell Embryo
Amplitude
Phase
Amplitude
Phase
Multi-Cell Blastocyst
Amplitude
Phase
Images by Dan Hogenboom, NU
November 18

19. Quadrature Imaging Microscope Design
Design Features
4 CCD Cameras - Balanced Mixing
10x and 20x Interchangeable Objectives
Virtual Pinhole Focusing System
November 18

20. Original Setup
November 18

21. Experiment vs. Analytical Model
Fiber Model: n=
Position - mm/pixel
-50 50 20 40 60 80
100 -3 -2 -1 1 2 3
Fiber in Sugar Water
Position - 0.9mm/pixel 50
100
150
200
250
300
350 -3 -2 -1 1 2 3
November 18

22. Unwrapped Phase Image of a Mouse Oocyte
Amplitude
Unwrapped Phase
Phase
10027.jpg
3993.jpg
10028.jpg
Mayl 02002
Chuck DiMarzio, Northeastern University

23. How Could QTM Count Cells in Compact Embryo?
QTM Phase
DIC
Assumed Index
Profile Before
Compaction
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9 1
1.1 -3 -2 -1 1 2 3
M10026.m
M10026.m
Assumed Index
Profile During
Compaction
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.5 1
1.5 2
2.5
M10026.m
M10026.m
Mayl 02002
Chuck DiMarzio, Northeastern University

24. Chuck DiMarzio, Northeastern University
Third Generation QTM Q .
Mayl 02002
Chuck DiMarzio, Northeastern University