An Introduction to nano-optics

Presenter: M. D. Talebzadeh

Who did Introduce Nano tech/Science?

• it is more like solid-state physics in the sense that it might tell us much of great interest about the strange phenomena that occur in complex situations.

• Why cannot we write the entire 24 volumes of the Encyclopaedia Britannica on the head of a pin?

• What good would it be to see individual atoms distinctly?

• it would be interesting in surgery if you could swallow the surgeon. You put the mechanical surgeon inside the blood vessel and it goes into the heart and “looks”around.

• Why can’t we manufacture very small computers? Why can’t we drill holes, cut things, solder things, stamp things out, mold different shapes all at an infinitesimal level? What I would like to suggest is the possibility of training an ant to train a mite to do this.

How Tiny!!

Can we see and make it?

The nature build them.

Nanotechnology

• 1. Nanotechnology involves research and technology development at the 1nm-to-100nm range.

• 2. Nanotechnology creates and uses structures that have novel properties because of their small sizes (at this level atoms leave the realm of classical physical properties behind, and venture into the world of quantum Mechanics).

• 3. Nanotechnology builds on the ability to control or manipulate at the atomic scale.

There are two ways to build a house…...

Top-down

Bottom-up

scanning tunneling microscope (STM)

• The “tunneling” of electrons (quantum tunneling) between the tip and the substance being viewed creates a current (flow of electrons). The strength of the current and how it changes over time can be used to create an image of the surface of the substance.

• Among other things, they can be used to move atoms around and arrange them in a preferred order.

atomic force microscope (AFM)

• uses a tiny tip that moves in response to the electromagnetic forces between the atoms of the surface and the tip. As the tip moves up and down, the motion is recorded and an electronic image of the atomic surface is formed.

Some construction methods

Atom-by-Atom Assembly

• it can be done but don’t necessarily have practical application because the process is expensive and slow.

Lithography is a Beast[ S. Kawata et al., Nature 412, 697 (2001) ]

2µm

λ = 780nm

resolution = 150nm

7µm

(3 hours to make)

One-PhotonHolographic Lithography

[ D. N. Sharp et al., Opt. Quant. Elec. 34, 3 (2002) ]

huge volumes, long-range periodic, fcc lattice…backfill for high contrast

10µm

Mass-production: Colloids

microspheres (diameter < 1µm)silica (SiO2)

(evaporate)

sediment by gravity intoclose-packed fcc lattice!

In Order To Forma More Perfect Crystal…meniscus

silica250nm

Heat Source

80C

65C1 micron silica spheresin ethanol

evaporate solvent

• Capillary forces during drying cause assembly in the meniscus

• Extremely flat, large-area opals of controllable thickness

A Better Opal [ fig courtesyD. Norris, UMN ]

[ figs courtesyD. Norris, UMN ]Inverse Opals

fcc solid spheres do not have a gap…

…but fcc spherical holes in Si do have a gap

Infiltration

sub-micron colloidal spheres

Template(synthetic opal)3D

Remove Template

“Inverted Opal”

complete band gap

~ 10% gap between 8th & 9th bandssmall gap, upper bands: sensitive to disorder

Inverse-Opal Photonic Crystal[ fig courtesy

D. Norris, UMN ]

[ Y. A. Vlasov et al., Nature 414, 289 (2001). ]

What is Light?

Propagation

Study of light: Electromagnetic Propagation

Ray Optics

Can we condense the Light?

Light Amplification by Stimulated Emission of Radiation

Laser:

Laser Applications

• Welding

• Cutting

• Etching

Nano optics/photonicsfundamentals

The Lycurgus Cup (glass; British Museum; 4th century A. D.)

When illuminated from outside, it appears green. However, whenIlluminated from within the cup, it glows red. Red color is due to very small amounts of gold powder (about 40 parts per million) embedded in the glass, which have an absorption peak at around 520 nm.

Trasmitted light is redSurface scattered light is green

What are PLASMONS?

• Coupled oscillations of charge carrier density and electromagnetic field (plasmon polariton)

• Solutions of Maxwell’s equation for metals

•Bulk plasmon modes•Surface plasmon modes

Plasmon coupling: Surface Plasmons

• Surface plasmons can propagate along a periodic chain of metallic nanoparticles

• Solution of Maxwell’s equation for a dielectric/metal interface

Combining PhC with Plasmonplasmons are like sieve for the light

Metamaterials and their applications

• Metamaterial– From Greek metà (beyond) + Latin materia

(material)– To-the-letter meaning: material that doesn’t

exist in nature– Physics meaning: material with negative

refractive index

Nano Solar Cells

• The researchers added single-walled carbon nanotubes to a film made of titanium-dioxide nanoparticles, doubling the efficiency of converting ultraviolet light into electrons when compared with the performance of the nanoparticles alone.

Solid state physicsat a glance!!

From Principles of Quantum Mechanics :

electrons are waves 1

waves in a periodic medium can propagate without scattering:

Bloch’s Theorem (1d: Floquet’s)

2

The foundations do not depend on the specific wave equation.

شبكه الكتروني يك بعديروش ترسيم يك ياخته ويگنر سايتس دوبعدي

( ) ( ) ikx

k

x C k eψ =∑

( ) [ ( )] ( ) ( ) ( )x P U x x xm c

ωψ ψ ψΗ = + =2 212

( )( ) ( ) ( )ikx i k G x ikxG

k G k k

k C k e U C k e C k em

ε++ =∑ ∑∑ ∑2

2

2

( ) ( ) ( )k GG

C k U C k Gλ ε− + − =∑ 0 kkm

λ =2 2

2

( ) ( )( ) ( )

( ) ( )( ) ( )( ) ( )

k g

k g

k

k g

k g

U U C k g C k gU U U C k g C k gU U U U C k C k

U U U C k g C k gU U C k g C k g

λλ

ελλ

λ

−

−

+

+

⎛ ⎞ ⎛ ⎞ ⎛ ⎞⎜ ⎟ ⎜ ⎟ ⎜− −⎜ ⎟ ⎜ ⎟ ⎜⎜ ⎟ ⎜ ⎟ ⎜− −⎜ ⎟ ⎜ ⎟ ⎜

=⎜ ⎟ ⎜ ⎟ ⎜⎜ ⎟ ⎜ ⎟ ⎜+ +⎜ ⎟ ⎜ ⎟ ⎜

+ +⎜ ⎟ ⎜ ⎟ ⎜⎜ ⎟ ⎜ ⎟ ⎜⎝ ⎠ ⎝ ⎠ ⎝

2 1 2

1 1 2

2 1 1 2

2 1 1

2 1 2

0 0 2 20

00 0 2 2

⎟⎟⎟⎟⎟⎟⎟⎟⎟⎠

k g

k g

k

k g

k g

U UU U UU U U U

U U UU U

λ ελ ε

λ ελ ε

λ ε

−

−

+

+

−−

− =−

−

2 1 2

1 1 2

2 1 1 2

2 1 1

2 1 2

0 00

000 0

Electronic and Photonic Crystalsatoms in diamond structure

wavevector

elec

tron

ene

rgy

Per

iodi

cM

ediu

mB

and

Dia

gram

dielectric spheres, diamond lattice

wavevector

phot

on f

requ

ency

Blo

ch w

aves

:

interacting: hard problem non-interacting: “easy” problem

{ }E

E

__

L̂ ( )

L̂ ( , ) ( , ) ( , )( )

eigen vectoreigen value

operator

E r t E r t E r tcrω

ε= ∇× ∇× =

2

2

1

}H

H

__

L̂ ( )

L̂ ( , ) ( , ) ( , )( )

eigen vectoreigen value

operator

H r t H r t H r tcrω

ε⎧

= ∇ × ∇ × =⎨⎩

2

2

1

[( ). ]( ) ( ) i k G rkn kn

G

E r E G e +=∑

Photonic Crystals(are micro/nano structures)

periodic electromagnetic media

1887 1987

with photonic band gaps: “optical insulators”

2-D

periodic in two directions

3-D

periodic in three directions

1-D

periodic in one direction

(need a more

complex topology)

Photonic Crystals in Nature

wing scale:

Morpho butterfly

6.21µm

[ L. P. Biró et al., PRE 67, 021907

(2003) ]

Peacock feather

[J. Zi et al, Proc. Nat. Acad. Sci. USA,100, 12576 (2003) ]

[figs: Blau, Physics Today 57, 18 (2004)]

(Waveguides don’t really need a complete gap)

Fabry-Perot waveguide:

We’ll exploit this later, with photonic-crystal fiber…

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Help!

Defect Flavors

a

So What?

Wide-angle Splitters

[ S. Fan et al., J. Opt. Soc. Am. B 18, 162 (2001) ]

Waveguide Crossings

[ S. G. Johnson et al., Opt. Lett. 23, 1855 (1998) ]

Channel-Drop Filters

[ S. Fan et al., Phys. Rev. Lett. 80, 960 (1998) ]

A Linear Nonlinear Filter

in out

Linear response:Lorenzian Transmisson shifted peak

+ nonlinearindex shift

Nano Photonics

Structure and construction

Fabrication by Lasers (Lithography)

Fabrication by Chemical Methods

Optical nano waveguides and lasers

Integrated photonics

References:

1- “2002 Photonics Design & Applications Handbook”, Writers: webmaster@laurin.com.2- Plasmon applications in PhC,Metamaterials and superfocusing effectsDaniele Masciarelli25 July 20073- Photonic Crystals:Principles and Applications, Steven G. JohnsonMIT Applied Mathematics4- S. G. Johnson and J. D. Joannopoulos, Photonic Crystals: The Road from Theory to Practice (Kluwer, 2002).

5- K. Sakoda, Optical Properties of Photonic Crystals (Springer, 2001).6- Nanoscale Assembly, WilhelmT.S.Huck, 2005 Springer.