Aspekte der modernen Optik - tu-chemnitz.de · Spektroskopie • Absorption, Emission von elektromagnetischer Strahlung (Optisch, Infrarot, Raman, Magnetische Resonanz, Photoelektronen),

Prof. Dr. C. von Borczyskowski

Aspekte der modernen Optik

Vorlesung vom 20.05.2010

Spektroskopie

30.000

'I. 'f ., k•

-~0 . .11 ~~ .. • ~

3 GH~

o ./.12. IrJ If"I'I, (' I Co'","", - A .10

~

Spektroskopie • Absorption, Emission von elektromagnetischer Strahlung

(Optisch, Infrarot, Raman, Magnetische Resonanz, Photoelektronen), Dieelektrische Spektroskopie, Akustische Spektroskopie

• Quantenmechanischer Ansatz: (Eigen-) Energien,Wellenfunktionen, Übergangsmomente

• Bom-Oppenheimer Näherung: Separation von Elektron-, Kembewegungen (Schwingungen)

• Heisenbergsche Unschärfe-Relation

• Kohärenz

• Kontinuums Ansatz: Dielektrische Konstante, Absorption, Brechungsindex, Reflexion, Polarisation

• &ektrale-, zeitliche Auflösung, Emefindlichkeit, Mikroskopie

Molecular Orbitals

• Covalent bonds, lonic bonds, Hydrogen bonds

• Linear Combination of Atomic Orbitals (LCAO)

• Hybridisation

• Important Atoms: • H -1 ~ )2 • C z .. (2 /j);' 2 .>( (2 1') t:1 r:·

• N 2-,,(2"3); $){(2.p)

• 0 2 x ( 2 0»;' I-{ J.: (2/')

· s '2 K Lj Cl) ) 4 x ( sI')

• Metalls: Fe, Zn, Mg, Mn, ...

2

c ,

verschmolzenes getrennte Atome Atom Molekül

0_,

. >.

;, -~:.~" '

". .,'

I. I.ls

0 0. .' .~" '.. .....:····,· 0·''',. "'· 0". '.. ' '.'.-' . . ,.' . . .. ,'

, .. " ,.'

2p~

2p"

Q()-(JQ

2p,

Bild 11.3 Beziehung zwischen den Orbitalen getrennter H-Atome, von H2<~..foJckülen und den Orbitalen dcs verschmolzenen He-Atoms

t:::_ ,,. _ ..,'

x

z i, z

•

]

x

c. (a) spZ-HybridwellenCunktionen (Il) P. Wcllcllfuilklioll

Abb. 5·20. WellenfuI'ktlonen, die aus sp'-Hybridisierung resultieren.

(5.10)

,'.

." "

", :)U

-'li

• .,

'. , "1 ,.)'

Abb.2.26. Form d., blnd.nd.n und .nUbmd.nd.n MO Im lJ.nzoImoIoIr.iJl ,,'

E

-3 -2 -1 o 1 2 3

k =-2

k=-1 * k=1

f

* k=O

• • •

"Jablonski-Oiagramm"

E

Ionisierungsgrenze

••

. ...

.. -•.... •;

ISC., -rS V 1 IC

I

.-•• ISC

ssionAbs.

Phosphoreszenz

iJ

! IC. . . ~ .. I

j •t 11 .1

~ ~ --

Emi

.-~ - .. -

-

Singlettzustände Triplettzustände

S = 0 S = 1

Energy Scheme: Jabonsky Diagram

• LeAO

• Hybridisation

• 2-Electron Levels.

• Pauli Principle

• HOMO - Lumo Orbitals (Highest occupied molecular orbital - lowest occupied molecular orbitals)

• Born-Oppenheimer Approximation

• Vibrations: - Bending

- Stretchin~

- Scetal modes

- Phonon modes

1 i

~

I

E 1,5-105 u

0,5 -105

0,95-105

cm-1

0,05 0,1 0,15 0,2

R(nm) •

f----X------j

•••

•••

•••

Oprical properties of organic molecules and aystals

\ \\ \ ,I

\ \1 I

\ Ij

S,

-==~_._-- .....[d s,

T, c:

.;;;ou ~ ',,:.g I

u crossingu c: c:

u.~

- u ~ -0

Ö. u0

.0 ~

.=:! « '.t..

s, _ ............_.L.I......_z.__......:.:.,'~_=_';';'O;...._......~.·Lb=d

...

c:" ... )1l r:: k.

--++-.--HI-l--.............-+--- __ ~~ter~.:t:~ __

k, 'k Intersystem04- _

c: .g Co

o .0 ~

<: f I

f-

I I o I Iu 1 I c: o I I 1 u I I I ..... ~ . I I I öu

I I I';::;-o 1 I I c..-= Co I ! ! :;I I , .1

~ I I I '_' ,_. -= :..... I I I ~

I I I ~

11. {111 5",,;.'.:,·..I'...l.1.L.' _

-------------

---------- ----

o r0

o C\J

l() N

............... -" ~)-- -,

r:::. __

----~-r------- .... \

-1..,\

"-... Cl VI

-(l

~I

-

/ __ f'" _.... -_.... <:...--

--_...> ------' ...._----- ----====:.~-,-----

r-==::: -------- ........ ----.:::----.r~~ _

-o o

fr_-_-=~:::---

--====3._____ -S---

.... r,,,

c-::-------"'" I

-----::"

-r0 1 o x I::.

~(,l' 6.. ~c~:1r e_c"~SI" f!!-IUf~~ !'1 . I .

W Molekül Absorption0>

E 5

Benzol 2550 $.1) 1

Naphthalin 3150 $.CO Anthracen 3800 $.CCQ

3 Tetracen 4800 $.A A A ACCCO Pentacen 5800 $.

A A A A ACCC'CCJ 2

" Ci O'----'-------'-----'-----'-------'""-----.....J

500 500 400

Alnml -

\

\

CCCJ 00\

\

Ci

20000 25000 30000 135000 cm

--~

Zeitauflösung, Empfindlichkeit

• Femtosekunden - Monate (22 Größenordnungen)·

'"• Isolation

• Stabilität

• Detektoren

• "Effekt" - Modulation

• Kodierung

• Markierung

Spektrale Auflösung

• Hei.;enbergsche Unschärferelation

• Homogene Verbreiterung durch dynamische Prozesse

• Inhomogene Verbreiterung durch statische "Unordnung"

• Ensemble- Zeitmittelung

• Kl'häiente Verfahren, DOllPel-"Resonanz"verfahren

• S1!...ektralc Selektion Lochbrennen), Einzelm(Ilekültechniken

a.z(w-w')

I I 1

I 1

1

1 I 1

1- 1-)" I 1

1

I 114--/::,_1

1

---....::::::::....-----i~---=::::::::..--------=::::::=- w w'

0<:(

Lf)

t'CO Lf)CH 3

. HF H

100<:(3NAN

0In1 0 t'-Lf)NyN

0 CHHF 3

eH 3

5900 5500 ~

0<:(

M ZLO -0 <..9LO 0::: 0

0<:(

Lf)

r--. co Lf)

6500 6100 5700

WAVELENGTH (Al

z l')

0:: o

0<J:

' >t

lfl r--Cl) Lf)

,,.

lf)

Z W tZ

z o lf) lf)

,, .

2: w

I .

6500 """61OlJ:' , 5700

WAVELENGTH'(ÄI I'

FIGo.1. The absorption and laser7 indu.ced (at 5700 A) emission spectra of DMST in' durene at 2 K.

(frort) 1-1. de Vrie~ ohd 1).A. v./le.\"s;mo; 'P~y~, Re.II. le1t-. 3"/~1, IH~;'

I 0 ,

I I

E~

0 0 0

, ~ '-', .j

"-'\ . ...

~y.

0 I ~

E' -u M

~ V\

oS

~

'E u

0 L.() ..-

I

0 ~

1O or

'-J o •

~ 0

I

"'\ it

T-x

N., - - '-'

•• ~1-- - - - -0

0 :0 \.0 or

..::so

=

J -

-..---------E u >

-o -..0

CL N

I

~-~-~-~-------------------.R10

E c

o <D \()

o 10 \()

c:o U

co I U C-:l<:: -Q..:'::

C~~8 N(1) N~ o

(1) I{)

o-IC)

@

0 o (j

(\J

o

@

.(1)

0 .

1 2 3 4 1 3 2 4

---f~-'.....:...'" +~[>

~-~-f- *--+ A* B A s·

Austüusch - vV2chselwirkung

1 2 3 4 1. 2 3 4

-t-t -t; L> •

+i--i-f- -ft--i-A· B A sf-

Coulomb - VIechselwirkung

--

'r", rlo1eküle

$1 fv

1.( 0"//////////(/I'!mn - "

JAA(k)h_~V

J 1\B (k)I !

tlEf . tlEf+tlD f n n n

So I:mn 1 ,

'\I

I 4

~nregungsenergie fUr Bandverschiebung durch die Bandstruktur und Davydov

9ine MolekUlanregung Ww mit den anderen MolekUlen Aufspaltung

:im MolekUl n. im Kristall. +,+

~Ef = «.,f IH Icl> tlDnf

- L «'f~fml Ymn Ilf~ f m> E f (k) = 2J cos kb n n An n + AA

mfn -+ -+ -+ -+ -+ -+

+2JAB[cosk(a+b)/2 + cosk(a-b;- <Cf IH Ilf ». <'fmlfn IYmn Ilfm:fn >).n An n .,,~ c.... •ß..... .c.I~ ..-A'~" ~

- <

0.000 cm-1 <tlE~ <30.000 cm-1 tlDf typisch'" 1.CXXl cm -1 D3.vydov-Aufspaltung T1 typisch 10 cm-1 n

!

_11$, 100 an '

--

cl

bl

el

c,.\

I i

v lern-' I 17200

1060 939

't I,

".--< I

I I

.k.,,,, , :

I

16800

-2. I,, , I

I

r I

0-0

rTf'

16LOO

0-0

f ,j!/

l_ • .\ i-~, 1....(.:..-1/'

l_-Jl_ !

~olebur :11 cre

.1

'\ . . .I

• ''--- _// ......',1

"

Fig. 1. Excitatio spect um of free-base porphin (H-z P) .: T ·4.2 K: (a) in n-heptane (CIYstal) with broadband detection of l1uorescence; (b) in MTHF (gIau) with broadband detection of l1uoresccnce; (c) in MTHF (gIau) wlth narrowband detectlon of nuoresoence; (d) in MTHF (gIass) wlth a photo • chemlcal hole burnt I to the 0-0 transition and br ,adband d.tectlc:m oe l1u( rt'S<'"mce.'0

; .

c .'2 d. ~

o Vl

.D o

v, Vo

pholoproduc.t

v, v •

.. \ '. .-

__~,....-~ Ar· -

I

8

1---

nA 'mfler

! _.l'· ! .....;~ ~j' .. . ,sempie-

L. ..... SL. ..

('~% ?:= " cryostot

PO }-- leser

'-----I LI 5

n A m~ler monochromator

r ,I

I IHV II PM 1I -----, I),-'.11

I FP L - __________ .J- -- .

Hlchelson· wavemeter

H "'N--.-,(\ ~

,

\

(1 ) .r;-;:;lSlil[ VL:.-J

H H

0-0

(2)

(1) (2)

(1) (1)

(2)

(2)

.....J"-~~----.Ä..--J\.- .

16331 16266 14700 cm- 1

Single Moleeule Detection

-Principles of Optical Spectroscopy of Organic Moleeules and Nanoparticles

-Single Moleeule Detection Schemes

-Application to Moleeules

-Application to Nanoparticles

Single Emitter

Single Emitter in a Crystal at low T

~~ I

>0) ..... Q) c Q)

"

~

zero phonon line

10 MHz (10-3-10-4 cm- 1)

phonon wing

frequency

1several 10 cm

• probes nano-environment static & dynamic properties

• providies information on the members of an ensemble

• may show up new physical effects

- blinking - photobleaching in one step - bunching/anti-bunching of photons

Geordnetes Gitter

I~

Y

I~

homogene Linie

1

c .2- 2 \.. o Vl

.D « 3 .. wW,·W,·W,

amorphes Gilte

\ \ '- 1'\2\ r

\

.J.. -.... ""'-.j...

\ ~IL--.......

( /'"' ) I

c: o.-Q.... o 1/1 .Q «

inhomogene Linie

2

(0

. '. ...

j\'AVE)!"L:-1BER / cm- 1

16886 16883

'. ".

/ 1-;",,.. ~'.f'". , -

-' • I" ..,. ~ ~ . f'

C

B

.,:••~ • ..l...

. .' .. ",: .. . '\.... .~

30 GHz

f---------I

".' .;, . . .': " ..:

UJ Z

z~~ ~-

D :_'_i_:'-----'''----'__'_,_,_~._·._.

+-E\CITATIO.\ fREQCE.\CY

II 500 .-- '.:c..""... -----,

""-..,

o ~

_.,

o .. /../. .. \ . , 0.05 GH:

EXCITATION FREQ(jE~CY

4l:.~ X ~ SI .... Jf ~ y11t'-' Jf

/

.MWI I

,II Z I / 9(}o~.sLASER '" ,'~

/VI I I

~

1 S_o",---__

~hV

-

III

!lilllll~11

80

70

60 . -+--' c Q) 50 ü c Q) 40 ü Cf) Q) 30I.

0 :::J 4 20

10

0

Terrylene moleeule undergoing quantum jumps to the triplet state

plus jL'mps to another (frequency) state

o 1000 2000 3000 4000 Time / 100f.ls

C /\ 0.- ~I

..p.lI -l. ICO 'lJ- '---' Q) '\l L- I ~\ L- 0e 0 .-0 -~ ~'" C)t) 'lJ c......

Ü '---- ~ .-(J)0 e I \'-\ co..p.lI :::J ~II"J ...c::J lL.

"~ C) c 0

e:::( e (1)

...c 0Co)0 II C).- CC ...... C::J 0 .-CO ~ ..c :.;::; ...c

Q) (-J :.;::; CO Co) I- --...~ C - C I- oe:( Co) :::J

'-.->0 ~,

I (J) ..c Ü <r\:::; c 0 c

0 I 0e -+-' -+-' 0 ..c 00...... ...c CO ...c

0 0.. 0:: 0.. ~ I I I0

•

Densityn1atrix 5 - Level System

• Microwave - optical Blochequation

W -0 cos W t 11 L

-0 cos W r w22

W A cos wJ xxH/h W yy

-A cos wrJ. zzL W

Brown et al.

J. C. P. 1994

Correlationfunction

2 (l(t) l(t+-r;)) g (-r;)=

(1(t))2

\f)

"T

0 0 0 ......-I

0 0 ......-I

0 ......-I

......-I

--;;2:

......-I

· P 0

......-I

0 •

0

......-I

0 0 · 0 ......-I

0

•

'.\'

. . .~ . ..\

,~---~, " . . , ..... ;, '\,

~\ . . -."".!,,) ,

~"l

'>""'! • .X I>~ .... ~

'-Z~0,' ~

\ 4: .~_.S d:l

C <iT',.. ..... . ~

~ ~,

r.f.\ ~ •.,., ..... ~.

"''"

I I I I I 1 0 0\f) M \f) (".l \f) ......-I \f)"T 0. . . . · 0M (".l ......-I 0

T- (97 '3

;- ~500 C/J

!!! ':;;000 c i5 \500 (j

..2 1,000o.c: Q 500

o

".:; 600

.:J ~

(] 400 o

J! ~

200

Q~,11 o 0 \'

{'. lf\. ...-Q L~-0"II~1 -::- "ilJY·.~~~~ ~ .-> \.;:~~ t:'3 0 ",\.~..... .... . ."'"'' '~:.~.:::'.::.:<~

-../ 0 n 100-100 ,J

Loser detuning (MHz)

~

ö3 c c 220 ('j

..c u 200 .'Jj ~ ---c 180 ;:; 0 160 '-' u

140 ~.->-.

120on c Il)

- 100 c Il)

80 ~

u c 60 Il)

40u on Il) .... 0 20 ;:; ~

>.I., 0

•

•

0 5 10 15 20 25 30 Optical Frequency (GHz)

--I

vvv coun s s)

o.. .p..

N (Xl

(Xl 0

f-L N 0

NOL----===

~~ ~# 00 -CDCD AA c:(J) c: f-LN

--=::...-----.J

Correlation spectroscopy on rnolecules undergoing frequency shifts

System: Pentacene in p-Terphenyl

3.5

~

;:l 3 cd

'-" ....:ro 2.5......--c'"C)....- 2 .....N c 1.5<I.l N <I.l '" '"'0 1 MI ;:l-~

0.5 0 50 100

Zeit (s)

Autocorrelation function of fluorescence intensity yields typicaI correlation times:

150 200

. ~ '-'

NbJ)

I 0.9

0.8 / 0.7 r

0.6 0.5

0.4

0.3

1 J

0.001 0.01 0.1 1 10 100 1000 10000 "C (ms)

--

1;' c: l-'(

400

350"r 300

250

200

150 1800

1600 ~~

I• .-, 1400

1200

1000 0 200 400 600

f [5]

, ?....,~

---

---

1000

~800"3 =600Cl Cl

~

.-~itj200 .fl-= 0

5 55 Time (s)

1000 ~

~800'" ~600 Cl Cl ~

~ '~200

.fl 0..s 0

9000 .

3 ~

Cl Cl Cl Col '-'

~ .~

-.fl 0

1:1 0

200

Time lß

Time (s)

A

155105

B

15 20

C

400 600

I

T=4.2 K Dye moleeules2000

0 0 5 10 15 20 25 30

Control--:::J 600 I

cu '-'

>. 300+-'

In C 0

+-' c Q)

0 5 10 -Q) () ~ T=4.2 K c Q)

600 () In Q) 300 ..... a :::J 0 u- 0 5 10 15 20 25 30

2000 I T I 1.5 K

1.1. . ~ .L~~""H"Lt", ..._ J. •• ,- J)r"~"""'''''', If'~(Glas)

i i i i i i01 I I i I i i

0 5 10 15 20 25 30 Laser detuning (GHz)

Dynamics of t1uorescence intensity of single Inolecules

I. confocal images of single R6G moleeules (scan 1.2 x 1.2 ~lIn2)1

• temporal evolution of fluorescence intensity of single molecules

-·-r--------.-- --_._-,--- 2 0 I--~-----r-'-----'-1 9 I f

,. 5

,.

\YW ~ ~-~~~ o 5 20 25 20 30 40 50

o.o~1

l __.__ .~ ..L--_-----,--_..........l..--_~__-L_~__--'-_

tJs tl s

I

0.1 /-lm

550 600 650 700

Wavelength (nn1)

NATURE· VOl 369 . 5 MAY 1994

-soo

400

300

~ - 200 r, ,Ir" ...... . ......

8 100 VJ ....... c=',0,

U 18thmin

50

20th min

o

okrJrjM'

Average fürfirst 17

~

min

,....;.

550 600 650 700 Wavelength (nm)

Nitrogen Vacancy Defect (N-V centre)

- induced by electron iradiation (electron energy >300 keV)

- different charge states known

- weil studied by PL, RAMAN, ESR,ODMR

- high photostability

3E 1

?

> Q) E

" ~1A L{) C '<:tr--., ~C'J

I / /,......<0

3A --~t-~

90000

12500

10000Cl>....... rn

~ X FWHM =0.33Jlm~ 7500 ....... c ::J o 5000ü

2500

00 1 2 3 4 5

lateral position (~m)

Gruber et al. Science 276 (1997) 2012

I

single N-V centers fluorescence spectrum dynamics

1.21 Iin diamond......... BOO

(\:::J

~ 600 Q) P 1.1üc: 400 '\ -l1.l ~ ü eil 200 ),1 \l1.l "",..... 0 zero phonon line ~ :::J 10

l:i=

600 650 700 750 BOO~O 900 0.1 1.0 10

'T (ms)

wavelength (nm)

~ '"8 ~ lifetime ODMR spectrum

--L./=--_ ~~.100 ,I , I

0.0

1,05'-1

.....:::J

ro

l1.l ü c: 095 ~ , t1}

~ 0,90 o :::J- 0851 !,t

, 2840 2860 2880 2900 2920

monoexp.: ,th=11.6±O.7ns "

500 1000 1500mlcrowave frequency (MHz) decay / (20ps/channel)

80000 ,-------------::;;-;:====:;:::::;::=================]1,

optical Frequency (GHz)

Many 60 l 2,! 1. I Molecules-""""" ,,50! ,I I i

. t d40 I :[ ,...-...

~ 76750 i:: I ,1\ I Jil I ,1"1111o

'-" "* 10 ~~!~,~!J lr,~/M 11~'\~1 ~~~~I~I~W~IWf\~~r~!I~~ OLl~~'-~-~.2

"ü'j o 0.5 1 1.5 2 2.5 3C (!) +

~ 73500 ü c (!)

Molecule1.ü Cfl

~

g 70250 LL

"'= '=" Moleeule1

L-----'--_-.ll-:----'----~-;:--~-'---T-;:I;---L-~I;----,----------;J670000 0.4 0.8 1.2 1.6

Pulse Duration (J..ls)

• •

N ~

<I N ~

0

t Q) ;>,c . -Cl.. x

"'0 a.> Q) IC ~

Q) Q) ;> -=::::::: "'0 -Cl.. ..c CO -=:::::::0 .....E ..ClQ) .....(J)(J) Q)

::::Jc 0 :!::: iQ)W c E Q) -=::::::: Q)

c 0) CO(\j 0 Q) ::::J E -=::::::: ..Cl "'0C.- 0 E>..c Q)"'O(J) c (J) cl.... . c .Q) Q)Q)...... .

E c~

c - 0

W ~o -0 c c 0 .0 c-o CO

E -c :;::; E CO .....Q)

/- -

/

ES:::J l.... E ..... cc o .-c..> 0 c 0Q) ..... ._ C.Q.. >

Cf) Q)c

(J) ::::J 0 Q) c Q) 0)

e Q)

Q) -..c

Aspekte der modernen Optik - tu-chemnitz.de · Spektroskopie • Absorption, Emission von elektromagnetischer Strahlung (Optisch, Infrarot, Raman, Magnetische Resonanz, Photoelektronen),

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