march 02002 chuck dimarzio, northeastern university 10100-1-1 ece-1466 modern optics course notes...

March 02002 Chuck DiMarzio, Northeastern University 10100-1-1

ECE-1466Modern OpticsCourse Notes

Part 1

Prof. Charles A. DiMarzio

Northeastern University

Spring 2002


ECE1466: Modern Optics

• Instructor: Chuck DiMarzio• Office Hours: Thu 2-4 or by appointment• E-mail: dimarzio @ ece.neu.edu• Web: Check frequently for new material

– http://ece.neu.edu/courses/ece1466/ece1466.html

• Course Mailing List: Use for general questions– mailto:[email protected]

– Send me e-mail and I will add your name.


Lecture 1 Overview

• Introduction– Why Optics?– A bit of history– Motivational Example; Microscope

• Administrivia– Course Layout– Grading– Syllabus


Why Optics?Absorption Spectrum of the Atmosphere

Absorption Spectrum ofLiquid Water

Index of Refraction

1nm 1m1m 1mm 1m 1km

1nm1m1m1km 1mm

from Jackson


Earthlight


A Bit of History

1900180017001600 200010000-1000

“...and the foot of it of brass, of the lookingglasses of the women assembling,” (Exodus 38:8)

Rectilinear Propagation(Euclid)

Shortest Path (Almost Right!)(Hero of Alexandria)

Plane of IncidenceCurved Mirrors(Al Hazen)

Empirical Law of Refraction (Snell)

Light as PressureWave (Descartes)

Law of LeastTime (Fermat)

v<c, & Two Kinds of Light (Huygens)

Corpuscles, Ether (Newton)

Wave Theory (Longitudinal) (Fresnel)

Transverse Wave, Polarization Interference (Young)

Light & Magnetism (Faraday)

EM Theory (Maxwell)

Rejectionof Ether, Early QM (Poincare, Einstein)


More Recent History

2000199019801970196019501940193019201910

Laser(Maiman)

Quantum Mechanics

Optical Fiber(Lamm)

SM Fiber(Hicks)

HeNe(Javan)

http://www.sff.net/people/Jeff.Hecht/chron.html

Polaroid Sheets (Land)Phase Contrast (Zernicke)

Holography (Gabor)

Optical Maser(Schalow, Townes)

GaAs(4 Groups)

CO2

(Patel)

FEL(Madey)

Hubble Telescope

http://members.aol.com/WSRNet/D1/hist.htm

Speed/Light (Michaelson)

Spont. Emission (Einstein)

Many New Lasers

Erbium Fiber Amp

Commercial Fiber Link (Chicago)


Some Everyday Applications

• Illumination

• Signaling

• Cameras; Film and Electronic

• Bar-Code Reader

• Surveying and Rangefinding

• Microscopy

• Astronomy


My Research Interests

• Biological and Medical Imaging– Acousto-Photonic Imaging (DOT and Ultrasound)

– Optical Quadrature Microscopy

• Landmine Detection– Laser-Induced Acoustic Mine Detection

– Microwave-Enhanced Infrared Thermography

• Environmental Sensing– Optical Magnetic Field Sensor

– Underwater Imaging with a Laser Line Scanner

– Hyperspectral Imaging Laboratory Experiments


Some Other Applications (1)

• Communication– Lasers and Fast Modulation

– Fibers for Propagation

– Fast Detectors

– Dense Wavelength Diversity Multiplexing

– Free-Space Propagation (Not Much)

• Optical Disk Memory– Lasers, Detectors

– Diffraction Limited Optics



• Photo Lithography for Integrated Circuits– Short Wavelength Sources– Diffraction Limited Optics

• Adaptive Optical Imaging– Non-Linear Materials or Mechanical Actuators

• Velocimetry and Vibrometry– Coherent Detection, Coherent Sources



• Hyperspectral Imaging– Dispersive Elements– Large Detector Arrays– Fast Processing

• Medical Treatment– Delivery– Dosimetry


Some Recent Advances

• Laser Tweezers

• Optical Cooling

• Entangled-States

• Fiber-Based Sensors

• Optical Micro-Electro-Mechanical Systems


Motivation: Designing a New Microscope

• It’s Not Just About Resolution– Resolution Limited by Diffraction

• It’s About What Is Measured– Transmission, Reflection, Phase, Fluorescence,

Polarization, Non-Linear Properties

• And About How Data Are Processed– Registration, Deconvolution, Tomography, Parameter

Estimation

• And About Measuring Everything at Once


Contrast Features

• Material Properties– Wavespeed

– Attenuation

– Birefringence

– Non-Linearity

• Composition: What are the materials?

• Quantitative Measurements: How much of each?

• Structure: How they are arranged?– Boundaries– Shapes


A Couple of Rules

• Frequency and Wavelength– =c where is frequency, is wavelength– c is the speed of light.

• Photon Energy– E = h where h is Planck’s constant

• Materials Absorb and Emit Photons with Corresponding Changes in Energy


Some Material PropertiesAbsorption

Energy

Emission Fluorescence

2-photon


3-D Fusion Microscope

DIC

QTM

TPLSM

LSCMRCM


Interference and Quadrature Microscopy

QWP

Object

CCD

CCD

Laser Source


Mouse Embryos with DIC

Image by Carsta Cielich in Carol Warner’s Laboratory at Northeastern University

4-Cell Embryo

2-Cell

1-Cell

Multi-Cell Embryo

m

Fragmented Cell

CompactedEmbryo


Mouse Oocyte with QTM

3993.jpg10027.jpg

10028.jpg

Unwrapped Phase

Phase

Amplitude


Reflectance Confocal;

VivaScope 1000 - imaging in vivo

Some 3D Scanning Microscopes

thanks to Badri Roysam, RPI

FluorescenceConfocal Two-Photon Microscope

100 200 300 400 500 600

100

200

300

400

500

100

200

300

400

500

100 200 300 400 500 600

pxl

pxl

pxl pxl


What Does Each Mode Contribute?

• DIC: – 2-D Structure

• QTM:– 2-D Phase, 3-D Index and Absorption

• RCM:– 3-D Structure

• LSCM:– 3-D Composition

• TPLSM:– 3-D Composition (Endogenous Fluorophores)


Why Use This Example?

• Important Application Area• Current Interest at Northeastern• Coverage of Important Topics

– Geometric Optics– Diffraction– Interference– Polarization– Non-Linear Optics– Lasers– Signals and Noise


Some Everyday Concepts (1)

• Specular and Diffuse Reflection• Refraction

Specular Diffuse Retro


Some Everyday Concepts (2)

• Imaging

Wavefronts


High-School Optics

F

F’

Object

Image


Basic Geometric Optics

• Reflection and Refraction• Imaging

– Real and Virtual– Image Location; Conjugate Planes– Magnification

• Transverse, Angular, Longitudinal

• Reflecting Optics (Not much in this course)• Refracting Optics


Reflection


Plane of Incidence

’’

• Contains Normal• Contains Incident Ray• And Thus Contains

Refracted Ray• Is the Plane Shown in

the Drawing• Angles

– Defined from Normal


Imaging

• First, Assume a Point Object– Spherical Wavefronts and Radial Rays Define

Object Location– Find Image Location– Real or Virtual?

• Next Assume an Extended Object– Compute Magnification

• Transverse, Longitudinal, Angular


Where Are We Going?

• Geometric Optics– Reflection– Refraction

• The Thin Lens– Multiple Surfaces– (From Matrix Optics)

• Principal Planes• Effective Thin Lens

– Stops• Field• Aperture

– Aberrations

Ending with a word about ray tracing and optical design.


The Plane Mirror (1)Point Object Extended Object

A A’-s’s

A A’

B B’

h x x’


The Plane Mirror (2)

dx’dy’ ds’

ds

dy

dx

x’=x m=x’/x=1Transverse Magnification

ds’=-ds mz=ds’/ds=-1

Longitudinal Magnification

’’= m=’’/=1Angular Magnification

Image is Virtual (Dotted lines converge)Erect (m>0),Perverted (can not rotate to object)but not distorted (|m|=|mz|)

(refer to pictureon left side ofprevious page)


Refracting Surfaces (1)

Snell’s Law

’’

n n’

0 10 20 30 40 50 60 70 80 900

5

10

15

20

25

30

35

40

45

50

Angle of Incidence

Ang

le o

f Ref

ract

ion

Air to WaterAir to GlassAir to ZnSe (10 m)Air to Ge (10 m)


Refracting Surfaces (2)

Snell’s Law

’

n n’

0 10 20 30 40 50 60 70 80 900

10

20

30

40

50

60

70

80

90

Angle of Incidence

Ang

le o

f Ref

ract

ion

Water to AirGlass to AirZnSe to Air (10 m)Ge to Air(10 m)

Critical Anglen

n'sin


Sign Definitions

• Object Distance, s– Positive to Left

• Image Distance, s’– For Refraction

• Positive to Right

– For Reflection• Positive to Left

• Notation– Capital Letter; Point

– Lower Case; Distance

– (Almost Always)

s s’

s’

s

A

A’

B

B’

FF’

f


Real and Virtual Images

• Real Image– Rays Converge

– Can Image on Paper

– Solid Lines in Notes

• Virtual Image– Extended Rays

Converge

– Dotted-Lines in notes


The Thin Lens (1)


The Thin Lens (2)

Front Focal LengthBack Focal Length

f f’


Special Case: Thin Lens in Air

Lens Makers Equation with d = 0Lens Equation

f f’


Imaging Systems H H’V V’

D’Dfs s’

f’

B B’

w w’

s, s’ are object and image distancesw, w’ are working distances


Principal Planes with Bending

-2 -1 0 1 2 3 4 5-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

p1, P

ower

of F

ront

Sur

face

, /cm

.

Locations: V, V',H,H'

P1+P2=0.1/cm, z 12=0.5 cm, n=1.5HH’=VV’/3 holds, except for extreme meniscus lenses.

H, H’ in lens from plano-convex to convex-plano.

Mensicus lenses not common.


Bending an IR Lens (Ge: n=4)

-0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

p1, P

ower

of F

ront

Sur

face

, /cm

.

Locations: V, V',H,H'

P1+P2=0.1/cm, z 12=0.5 cm, n=4

HH’=VV’X3/4 for n=4, over a wide range of bending.

Meniscus lenses are more common in the IR because of the high indices of refraction, as we will see later.


Some Optical Failures

f’f

Right Focal Length,Wrong Principal PlanesFor the Application

Meniscus Lens forInfrared Detector

march 02002 chuck dimarzio, northeastern university 10100-1-1 ece-1466 modern optics course notes...

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