July 2003+ © Chuck DiMarzio, Northeastern University 11270-01a-1 ECEG105/ECEU646 Optics for Engine6ers Course Notes Part 1: Introduction Prof. Charles

July 2003+ © Chuck DiMarzio, Northeastern University 11270-01a-1

ECEG105/ECEU646 Optics for Engine6ers

Course NotesPart 1: Introduction

Prof. Charles A. DiMarzio

Northeastern University

Fall 2008

Sep 2008


Lecture 1 Overview

• Administrivia– Course Layout– Grading– Syllabus

• Introduction– Why Optics?– A bit of history– Our Approach


Why Optics?Absorption Spectrum of the Atmosphere

Absorption Spectrum ofLiquid Water

Index of Refraction

1nm 1m1m 1mm 1m 1km

1nm1m1m1km 1mm

from Jackson

Sep 2008


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)

Sep 2008 http://www.sff.net/people/Jeff.Hecht/chron.html http://members.aol.com/WSRNet/D1/hist.htm


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)

Sep 2008


The First Laser?

Malibu, 1960

The First Laser

News Photo of the First Laser

?

"Laser, inter eximia naturae dona numeratum plurimis compositionibus inseritur*" "The laser is numbered among the most miraculous gifts of nature and lends itself to a variety of applications." Pliny, Natural History XXII, 49

Jan 2005


Some Everyday Applications

• Illumination

• Signaling

• Cameras; Film and Electronic

• Bar-Code Reader

• Surveying and Rangefinding

• Microscopy

• Astronomy


My Research Interests

• Biological and Medical Imaging– Multi-Modal Microscopy

– 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

Jul 2007


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

• Squeezed States

• Entangled-States

• Fiber-Based Sensors

• Optical Micro-Electro-Mechanical Systems


Some Everyday Concepts (1)

• Specular and Diffuse Reflection

• Refraction and Transmission

Specular Diffuse Retro

Dec 2004


Example InteractionsSlab Transmission Slab Absorption and

Scattering

Mostly DiffuseReflection

Specular with some Diffuse Reflection

Dec 2004


Some Everyday Concepts (2)

• Imaging

WavefrontsRays

The Observer The Observer

Object Image

Object Image

Sep 2007


Imaging

Jul 2007

Sep 2007

Near Card Demonstrates Camera is Focused Closer than Lens


High-School Optics

F

F’

Object

Image

Stopped Here 4 Jan 05


Our Approach

• Maxwell’s Equations

• Wave Equation

• Scalar Wave Equation

• Geometric Optics

• Polarization

• Interference

• Diffraction

• Radiometry

stopped 12 Sep 03


Maxwell’s Equations

Jul 2007


Maxwell’s Equations

• Source-Free Region

– No or J• Isotropic Medium

– E Parallel to D

• Harmonic Functions

– No Nonlinear Effects


Getting to the Wave Equation

H B

ED

Almost everything interesting is here


The Goodies are in Epsilon

H B

ED

H B

ED

More on this later in the course.


The General Problem• Goals

– Solve Maxwell’s Equations

– Satisfy Boundary Conditions

• Approaches– Special Cases (eg. Plane, Spherical, etc.)

– Approximations• Circuit Theory (>>D)

• Wave Theory ( D)

• Geometric Optics (<<D)


Steps to Geometric Optics

• Maxwell’s Equations

• Vector Wave Equation

• Scalar Wave Equation

• General Wave Solution

• Eikonel Equation (zero-wavelength approximation)


Vector Wave Equation

Jan 2005

H B

ED

Sep 2007

1

2

3

4


Scalar Wave Equation

H B

ED

Linear, Isotropic Medium

1

2

3

4

(Two States of Polarization)

Sep 2007


Eikonel Equation (1)



0 2



• L(r)=Constant Defines Wavefronts

– Thus, Wavefronts Are Perpendicular to Rays

• Define Optical Path Length

– Compare Travel Time to Light in Vacuum

n1 n2 n3n5n4

ΔL=∑ ni ℓi


Plane Waves

Scalar Wave Equation

General Solution

Plane-Wave Solution E=E0ei n k⋅r−ωt

Plane-Wave in z Direction E=E0ei nkz−ωt

Dec 2004


Optical Path Concept

• Not to Be Confused with Image Location

Physical DistanceImage Distance

OPL


Fermat’s Principle

• Where Does Ray Go?– Minimize Optical Path

• Imaging:– Many Minimal Paths

July 2003+ © Chuck DiMarzio, Northeastern University 11270-01a-34Jan 2005

July 2003+ © Chuck DiMarzio, Northeastern University 11270-01a-35Dec 2004 Stopped Here Thu 6 Jan 05

Documents

July 2003+ © Chuck DiMarzio, Northeastern University 11270-01a-1 ECEG105/ECEU646 Optics for Engine6ers Course Notes Part 1: Introduction Prof. Charles