Transcript Opticks

光学 OPTICS
叶 贤 基 教授
[email protected]
Phone: 87558393
Textbook:
Optics (3rd or 4th Ed.), Eugene Hecht
光学（改编版）高等教育出版社
Reference:
Principles of Optics, M. Born & E. Wolf
物理光学，梁铨廷，电子工业出版社
Assessment
Homework (20-30%)
• A few for each chapter
• Only partial marks if submitting after due date
Final exam (80-70%)
• Closed-book
• 2.5 hours
• 1 brief-explanation and/or 5-6 calculation questions
What is light?
Particle? or Wave?
Inspired by The History of Optics
Illustrations of various optical instruments
from the 1728 Cyclopedia
Modern optics laboratory
Timeline of Optics
~ 400 BC
Aristophanes
Lens, glass …
1818
A.-J. Fresnel
Diffraction of light
wave
Polarization
(transverse wave)
1621
Willebrord Snellius
Snell’s law
1678
C. Hyugens
Principle of
wavefront
sources
130
C. Ptolemy
In his work “Optics”:
Reflection, refraction,
color and tabulated
angle of refraction
1657
Pierre Fermat
Principle of least time
1600
~ 300 BC
Euclid
The first to write about
reflection and refraction
1746
L. Euler
Wave theory of
light refraction
and dispersion
1700
1801
Thomas Young
Young’s exp.
(wave nature of
light, and
interference)
1800
1676
O. Roemer
Measure the speed
of light by observing
Jupiter’s moon
1611
J. Kepler
• How the light focuses light
• Laws of the rectilinear propagation of light
• Discover total internal reflection
1873
J.C. Maxwell
Light = e.m. wave
1900
1862
Leon Foucault
c=2.98108 m/s
1704
Isaac Newton
Opticks
1818
Simeon Poisson
Poisson-Arago bright spot
Pierre de Fermat
Fields: Mathematics and Law
Known for:
Analytic geometry
Probability
Fermat's Last Theorem
(Singh, Simon (2002). Fermat's Last Theorem. Fourth Estate Ltd.)
•
•
Fermat's principle is the principle that the path
taken between two points by a ray of light is the
path that can be traversed in the least time. This
principle is sometimes taken as the definition of a
ray of light.
Fermat's principle of least time was the first
variational principle enunciated in physics. In this
way, Fermat is recognized as a key figure in the
historical development of the fundamental
principle of least action in physics.
Timeline of Optics
~ 400 BC
Aristophanes
Lens, glass …
1818
A.-J. Fresnel
Diffraction of light
wave
Polarization
(transverse wave)
1621
Willebrord Snellius
Snell’s law
1678
C. Hyugens
Principle of
wavefront
sources
130
C. Ptolemy
In his work “Optics”:
Reflection, refraction,
color and tabulated
angle of refraction
1657
Pierre Fermat
Principle of least time
1600
~ 300 BC
Euclid
The first to write about
reflection and refraction
1746
L. Euler
Wave theory of
light refraction
and dispersion
1700
1801
Thomas Young
Young’s exp.
(wave nature of
light, and
interference)
1800
1676
O. Roemer
Measure the speed
of light by observing
Jupiter’s moon
1611
J. Kepler
• How the light focuses light
• Laws of the rectilinear propagation of light
• Discover total internal reflection
1873
J.C. Maxwell
Light = e.m. wave
1900
1862
Leon Foucault
c=2.98108 m/s
1704
Isaac Newton
Opticks
1818
Simeon Poisson
Poisson-Arago bright spot
Isaac Newton
Fields: physics, mathematics, astronomy
Known for:
Newtonian mechanics, Universal
gravitation, Calculus, Optics
•
From 1670 to 1672, Newton lectured on optics. During this period he investigated the
refraction of light.
•
He observed that colour is the result of objects interacting with already-coloured light rather
than objects generating the colour themselves.
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The first known functional reflecting telescope, today known as a Newtonian telescope.
Using Newton's rings to judge the quality of the optics for his telescopes.
•
In his Hypothesis of Light of 1675, Newton posited the existence of the ether to transmit
forces between particles. The contact with the theosophist Henry More, revived his interest in
alchemy. He replaced the ether with occult forces based on Hermetic ideas of attraction and
repulsion between particles.
•
In 1704 Newton published Opticks. He considered light to be made up of extremely subtle
corpuscles, that ordinary matter was made of grosser corpuscles.
Elements of the Philosophy of Newton is a book written by the
philosopher Voltaire in 1738 that helped to popularize the theories
and thought of Isaac Newton.
Chapter 1
Chapter 2
Chapter 3
Chapter 4
Chapter 5
Chapter 6
Chapter 7
Chapter 8
Chapter 9
Chapter 10
Chapter 11
Chapter 12
Chapter 13
Chapter 14
Chapter 15
…
Chapter 25
What Light is, and in What manner it comes to us.
The Property, which Light has of reflecting itself, was not truly known.
It is not reflected by the solid Parts of Bodies as vulgarly believed.
Of the property which Light has of refracting in passing from one Substance into another,
and of taking a new Course in its Progression.
Of the Form of the Eye, and in what manner Light enters and acts in that Organ.
Of Looking–Glasses, and Telescopes: Reasons given by Mathematicians for the Mysteries of Vision;
that those Reasons are not altogether sufficient.
In what Manner we know Distances, Magnitudes, Figures, and Situations.
Of the Cause of the breaking of the Rays of Light in passing from one Medium to another;
that this Cause is a general Law of Nature unknown before Newton;
that the Inflection of Light is also an Effect of the same Cause.
The wonderful Effects of the Refraction of Light.
The several Rays of Light have all possible Colours in themselves; what Refrangibility is. New Discoveries.
The Cause of Refrangibility; from which it appears that there are indivisible Bodies in Nature.
Proof that there are indivisible Atoms, and that the simple Particles of Light are Atoms of that kind.
Discoveries continued.
Of the Rainbow; that Phenomenon a necessary Effect of the Laws of Refrangibility.
New Discoveries touching the Cause of Colours, which confirm the preceding Doctrine;
Demonstration that Colours are occasioned by the Density and Thickness of the Parts of which Bodies are
composed (or the Thickness of the Parts that compose the Surfaces only).
Consequences of these Discoveries. The mutual Action of Bodies upon Light.
Of the Resemblance between the seven Primitive Colours and the seven Notes in Musick.
Introductory Ideas concerning Gravity and the Laws of Attraction.
Of the second Inequalities of the Motion of the Satellites, and the Phaenomena that depend thereon.
Regarding Newton’s “Opticks”
Opticks is largely a record of experiments and the deductions made
from them.
This work is not focused only on geometrical optics, but also
covering a wide range of topics in what was later to be known as
physical optics.
In this book Newton sets forth in full his experiments. His
experiments on these subjects and on the problems of diffraction
(which he never fully mastered) set the subject of optics on a new
level.
Opticks and the Principia
Opticks differs in many aspects from the Principia.
(1) Unlike the Principia, Opticks is not presented in a strictly
geometric form, with propositions proved by mathematics from
either previous propositions or lemmas or first principles (or
axioms). It does not prove its propositions by the use of ratios or
equations, or by the tools of mathematics. Rather, the proofs
generally proceed "by Experiments."
Other scientists followed Newton's lead. They saw that he had been
setting forth a kind of exploratory natural philosophy in which the
primary source of knowledge was experiment. This Newtonian
tradition of experimental natural philosophy was different from the
one based on mathematical deductions.
Timeline of Optics
~ 400 BC
Aristophanes
Lens, glass …
1818
A.-J. Fresnel
Diffraction of light
wave
Polarization
(transverse wave)
1621
Willebrord Snellius
Snell’s law
1678
C. Hyugens
Principle of
wavefront
sources
130
C. Ptolemy
In his work “Optics”:
Reflection, refraction,
color and tabulated
angle of refraction
1657
Pierre Fermat
Principle of least time
1600
~ 300 BC
Euclid
The first to write about
reflection and refraction
1746
L. Euler
Wave theory of
light refraction
and dispersion
1700
1801
Thomas Young
Young’s exp.
(wave nature of
light, and
interference)
1800
1676
O. Roemer
Measure the speed
of light by observing
Jupiter’s moon
1611
J. Kepler
• How the light focuses light
• Laws of the rectilinear propagation of light
• Discover total internal reflection
1873
J.C. Maxwell
Light = e.m. wave
1900
1862
Leon Foucault
c=2.98108 m/s
1704
Isaac Newton
Opticks
1818
Simeon Poisson
Poisson-Arago bright spot
Thomas Young
Fields: Physics, Physiology, Egyptology
Young established himself as a physician in London, so as Young published many of his
first academic articles anonymously to protect his reputation as a physician.
Wave theory of light
In the early 1800s Young put forth a number of theoretical reasons supporting the wave
theory of light, he must overcome the century-old view, expressed in the venerable
Isaac Newton's "Optics", that light is a particle.
Young's modulus
Young described the characterization of elasticity that came to be known as Young's
modulus, in 1807.
•
•
Barr, E. Scott (1963). "Men and Milestones in Optics. II. Thomas Young". Applied Optics 2:
639-647.
Robinson, Andrew (April 2006). "Thomas Young: The Man Who Knew Everything". History
Today 56: 53-57.
Timeline of Optics
~ 400 BC
Aristophanes
Lens, glass …
1621
Willebrord Snellius
Snell’s law
130
C. Ptolemy
In his work “Optics”:
Reflection, refraction,
color and tabulated
angle of refraction
1678
C. Hyugens
Principle of
wavefront
sources
1746
L. Euler
Wave theory of
light refraction
and dispersion
1657
Pierre Fermat
Principle of least time
1600
~ 300 BC
Euclid
The first to write about
reflection and refraction
1818
A.-J. Fresnel
• Diffraction of
light wave
• Polarization
(transverse wave)
1700
1801
Thomas Young
Young’s exp.
(wave nature of
light, and
interference)
1800
1676
O. Roemer
Measure the speed
of light by observing
Jupiter’s moon
1611
J. Kepler
• How the light focuses light
• Laws of the rectilinear propagation of light
• Discover total internal reflection
1873
J.C. Maxwell
Light = e.m. wave
1900
1862
Leon Foucault
c=2.98108 m/s
1704
Isaac Newton
Opticks
1818
Simeon Poisson
Poisson-Arago bright spot
Augustin-Jean Fresnel
Fields: Physics
Known for: wave optics
His discoveries and mathematical deductions, building on
experimental work by Thomas Young, extended the wave
theory of light to a large class of optical phenomena.
In 1818 Poisson deduced from Fresnel's theory the necessity of a bright spot at the centre of
the shadow of a circular opaque obstacle. With his counterintuitive result, Poisson hoped to
disprove the wave theory; however Dominique Arago experimentally verifed the prediction.
The existence of the spot had previously been observed in 1723 by Giacomo F. Maraldi, but
the work had been largely unrecognized.
Fresnel wrote to Young in 1824: in himself “that sensibility, or that vanity, which people call
love of glory, had been blunted.” … “All the compliments that I have received from Arago,
Laplace and Biot never gave me so much pleasure as the discovery of a theoretic truth, or the
confirmation of a calculation by experiment.”
Timeline of Optics
~ 400 BC
Aristophanes
Lens, glass …
1818
A.-J. Fresnel
Diffraction of light
wave
Polarization
(transverse wave)
1621
Willebrord Snellius
Snell’s law
1678
C. Hyugens
Principle of
wavefront
sources
130
C. Ptolemy
In his work “Optics”:
Reflection, refraction,
color and tabulated
angle of refraction
1657
Pierre Fermat
Principle of least time
1600
~ 300 BC
Euclid
The first to write about
reflection and refraction
1746
L. Euler
Wave theory of
light refraction
and dispersion
1700
1801
Thomas Young
Young’s exp.
(wave nature of
light, and
interference)
1800
1676
O. Roemer
Measure the speed
of light by observing
Jupiter’s moon
1611
J. Kepler
• How the light focuses light
• Laws of the rectilinear propagation of light
• Discover total internal reflection
1873
J.C. Maxwell
Light = e.m. wave
1900
1862
Leon Foucault
c=2.98108 m/s
1704
Isaac Newton
Opticks
1818
Simeon Poisson
Poisson-Arago bright spot
James Clerk Maxwell
Fields: Physics and Mathematics
Known for:
Maxwell's equations
Maxwell distribution
Maxwell material
•
•
•
•
Around 1862, Maxwell calculated that the speed of propagation of an
electromagnetic field is approximately that of the speed of light. He considered
this to be more than just a coincidence.
His famous equations, in their modern form of four partial differential equations,
first appeared in his textbook “A Treatise on Electricity and Magnetism” in 1873.
In 1866, he formulated statistically, independently of Boltzmann, the Maxwell–
Boltzmann kinetic theory of gases. His formula, called the Maxwell distribution,
gives the fraction of gas molecules moving at a specified velocity at any given
temperature.
Maxwell published a famous paper "On governors" in the Proceedings of Royal
Society, vol. 16. This paper is quite frequently considered a classical paper of the
early days of control theory.
Timeline of Optics
~ 400 BC
Aristophanes
Lens, glass …
1818
A.-J. Fresnel
Diffraction of light
wave
Polarization
(transverse wave)
1621
Willebrord Snellius
Snell’s law
1678
C. Hyugens
Principle of
wavefront
sources
130
C. Ptolemy
In his work “Optics”:
Reflection, refraction,
color and tabulated
angle of refraction
1657
Pierre Fermat
Principle of least time
1600
~ 300 BC
Euclid
The first to write about
reflection and refraction
1746
L. Euler
Wave theory of
light refraction
and dispersion
1700
1801
Thomas Young
Young’s exp.
(wave nature of
light, and
interference)
1800
1676
O. Roemer
Measure the speed
of light by observing
Jupiter’s moon
1611
J. Kepler
• How the light focuses light
• Laws of the rectilinear propagation of light
• Discover total internal reflection
1873
J.C. Maxwell
Light = e.m. wave
1900
1862
Leon Foucault
c=2.98108 m/s
1704
Isaac Newton
Opticks
1818
Simeon Poisson
Poisson-Arago bright spot
Timeline of Optics
Nonlinear optics
1879
A.A. Michelson
Interferometer
C=299,91050km/s
…
C=299,77411km/s
1873
J.C. Maxwell
Light = e.m. wave
1800
1905
A. Einstein
Special relativity
1960
T Maiman
LASER
1900
Quantum optics
• Quantum informatics
• Quantum manipulation
• Quantum measurement
• Atom optics
2000
Space interferometry
1905
A. Einstein
Photoelectric effect
1900
Max Planck
Black body radiation
1953
C.H. Townes
MASER
Various aspects of the nature of light
Thomas Kuhn,
The structure of scientific revolutions
“Paradigm”
Thomas Kuhn,
The structure of scientific revolutions
“Paradigm”
What are you looking at?
Some key points of Kuhn’s
“The Structure of Scientific Revolutions”
•
A Paradigm is ...? Kuhn baptizes his famous notion of a scientific
"paradigm" as originating from the "great works" of science, like
Newton’s Principia. These great works became paradigms because
they were sufficiently unprecedented to attract an enduring group of
adherents away from competing modes of scientific activity.
•
Discoveries are Rare Because Expectations Obscure our Vision.
•
No Paradigm Change without Crisis.
•
New Paradigms Place New Relations Amongst the Data.
•
Science is Non-Cumulative Because Terms Change their Meanings.
•
Paradigms Transform Scientists’ View of the World.
• The development of science doesn’t follow the logic
and sequence of the textbooks.
• Experiments is not only the primary source of
knowledge but also the final judgment of a theory.
• Existence of various courses is a convenient way for
teaching and learning, but nature is a complete
reality that cannot be separated into pieces. That is,
you must learn the connections among these courses
and build up the structure beyond physical theories
by yourself.
• Challenge authority (e.g. professors).
Be the host of yourself (active & responsible)
Unique Properties of Laser Light
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High monochromaticity (treating as a single-frequency wave)
High degree of both spatial and temporal coherence (strong
correlation in phase)
High directionality (small beam divergence)
High Power Nd:glass Laser
Frequency/Intensity Stabilized
He-Ne Laser
Laser Machining & Manufacturing
40 m square holes drilled in human
hair with an ArF excimer laser
Laser cutting
A medical stent micromachined from a
biodegradable polymer using a femtosecond laser
Optical Tweezer and Laser Cooling
Gravitational Waves Detection
The Laser Interferometer Space Antenna (LISA)
Classical Optics at a First Glance
Particle’s aspect
(Geometrical optics)
Wave’s aspect
(Physical optics, wave optics)
scattering
diffraction
reflection
refraction
interference
Schedule
Chap. 1 Introduction& Light (2 hours)
• A brief history
Chap. 2 Electromagnetic Theory & Light (6 hours)
• Harmonic waves
• Maxwell’s equations
• Photon energy & momentum
• Light in bulk matter
Schedule
Chap. 3 The propagation of Light (6 hours)
• Scattering, reflection & refraction
• Snell’s law & Fresnel’s equations
• Total internal reflection
Chap. 6 The Superposition of Waves (4 hours)
• Fourier series
• Coherence time & coherence length
Chap. 9 Polarization (10 hours)
• Polarized light
• Scattering & polarization
• Reflection & polarization
• Polarizers, retarders, optical modulators
Schedule
Chap. 7 Interference (10 hours)
• Required conditions
• Wavefront-splitting interferometers
• Amplitude-splitting interferometers
• Types of interference fringes
• Multi-beam interference
• Applications of interferometry
Chap. 8 Diffraction (8 hours)
• Fraunhofer diffraction
• Fresnel diffraction
• Kirchhoff’s scalar diffraction theory