Email: qhgong@pku.edu.cn20042005 200571

10-15 S---- (< 4.0fs) ---- (100TW) 1020W/cm2 3.5 1016W/cm2 1012bar 1bar 1021g g 109Gauss 0.5Gauss

...Femtoscience PWas

1878Muybridge2411/1000 $25000

Ultrafast time resolved measurementTimeaspszsfs10-18 s10-15 s10-12 s10-21 s

1 Femtosecond OKE measurementOKE signal intensityIs =

OKE -----

l : 760 - 850nmt : 100fsP: 1.5W, 76MHzI1:I2 = 10:1

------ Low costeasy of fabricationfast NLO responselarge off-resonant c(3)-p } fs measur.

Typical OKE signal for the reference sample CS2

To avoid the difficulty in giving an absolute values of light intensity and the interaction length, reference measurement was employed:CS2 as the reference sample 3=110-13 esuEvaluation of c(3) and g for the sample

C- p c(3) (g)10-29-10-35esu

Reported values about NLO of C60 and its derivatives

Molecule

Method(s)

Wavelength(nm)

Time

((3)(10-14esu)

((10-35esu)

C60

z-scan, DFWM

497

0.5ps

-1300(300

C60

OKE

640

fs

16000

C60

OHD-OKE

647

ns

-27.5

C60

OKE

810

fs

The OKE signals of o-xylene and C60 solution in o-xylene with a Molar concentration of 8.410-3 M. Triangle for o-xylene and the circle for C60 solution.C60 g

C60-(NH2CN)-C60(NH2CN)5Synthesis of different C60 derivatives

Symmetrical and sharp OKE response indicates the NLO response contributed from -electrons

Linear dependence of c(3) on the molecular concentration

Absorption spectra no-resonant NLO response

200

400

600

800

1000

0

1

2

3

4

C

70

-poly-aminonitrile

poly-aminonitrile

C

70

Absorption (A.U.)

Wavelength (nm)

1p 2

C60

C70

C60 ( NH2CN )6

C70 ( NH2CN )6

CuPc-C60

9.0(10-35 esu 5.0(10-34 esu3.2(10-33 esu

1.6(10-32esu

5.4(10-31 esu

C60-5(NH2CN)C60-5(NH2CNNCNH2)

C70-5(NH2CN)

C70 -5(NH2CNNCNH2)

1.0(10-32esu

3.5(10-32esu

4.1(10-32 esu

5.8(10-32 esu

3rd NLO response of single-wall carbon nano-tube

1Theoretical prediction ( Xie&Jiang) Armchair:Zigzag:In unit1032esu

C70

C70*

C60910

C60518

(xxxx

0.051

0.05163

0.133

0.148

(yyyy

0.051

0.05163

0.133

0.148

(zzzz

0.063

0.08165

3.123

2.783

(xxyy

0.016

0.01411

0.046

0.05

(yyzz

0.031

0.05435

0.194

0.062

(zzxx

0.031

0.05435

0.194

0.062

(av

0.064

0.08623

0.85

0.686

Determination of length distribution of tubes

The length distribution of SWCNs in water, determined by laser scattering method at wave length of 514.5 nm.

OKE Signal of C-nanotube at different concentration

: f =1.3nm, L=160nm) 2.110-28esu nano-tube 7.710-33esu C60 < 1.510-36esu

2(ZL02100479.X)

Ti : sapphire

laser

probe

Lock-In

Chopper

Delay Line

pump

Ge

PSD

3400-900nm 200fsQELS Technical Digest(USA,2001)212

JOPA 4(2002)152 JOPA 5(2003)123

GaAs

4 1-2/100fs

S0S1t1 < t2 < t3l1< l2 < l3

C152480nm500nm510nm530nm550nm570nmC152

3,3-(3-)CC11

H

H

H

S

N

C

3

H

6

S

O

3

-

H

+

H

H

H

S

N

C

3

H

6

S

O

3

-

+

O

H

H

HN(C

2

H

5

)

3

+

S

N

C

3

H

6

S

O

3

-

+

S

N

C

3

H

6

S

O

3

-

HN(C

2

H

5

)

3

+

(a) 1,1'-Diethyl-4,4'-cyanine. (b) 3,3'-Di(3-sulfopropyl)-thiacyanine,triethylaminium salt. ( c ) The excited potential surface of a barrierless isomerization reaction.BFO--Sink

3,333TCTiO2 33TCBFO485nmTiO2TiO233TC535nmTiO2TiO233TC

5

DCM @ 310-4mol/l, excitation @ 400nm 107

10-15s)

Near Infrared fs Pulsestransparent materialsMultiphoton In

Interaction areaablation, microexplosion, densification, compaction, Polymerization refractive index changewaveguides, couplers, gratings, photonic crystals, holes, channels, voids, Date storage XYZ

Fused silica absorption bandgap is ~9eV,IR fs laser beam: 800nm (~1.55eV) multiphoton processVoid array inside fused silicaSize of void :280nm AFM measur.300nJ, 120fs 800nm laser pulses NA=0.65 High intensity microexplosion (void)1

Size of void in different depth20mm/layer 2mm thickness disc 100 layers of bit plane can be written storage density of 1.2Tbit/cm3

Readout contrast for different recording layer Contrast = Imax / I0

18 layers

100m-

Opt. Exp. (2005)

2 Femtosecond laser multi-photonFabrication in transparent dielectric mediaLow intensity refractive index changeFilamentation in fused silica

Writing condition Energy dependence (fused silica)

J. Opt. A, Vol. 6 (8), 787 (2004) triangle region pulse duration: 130 fs to 230 fs pulse energy: 0.35 mJ to 1.5 mJfor the fabrication of refractive index modulationWriting Conditions - energy & pulse durationThe dependence of refractive index modulation threshold () and damage threshold () on pulse duration microscope objective (4, NA=0.10)

Writing Conditions - Scanning repetition123456

Dependence of the refractive index-modulation on scan repetitions Proceedings of SPIE, Vol. 5646, 480 (2005)

Diffractive efficiencyAs high as 92.9% efficiency was obtained. Other reports about 70%

Stability of refractive index modulationUnder room temperature and denote 1,2,4,8 and 12 time

Fabrication of Beam Shapers in Bulk Fused Silica grid grating line scanning of the femtosecond laser, 2 mJ, 10 mm/s, period of 5.2mm, 4-repetition diffraction patterns performed by a He-Ne laser normally incidentincident at the Bragg angles

square grating2 mJ, speed of 10mm/s, period of 5.2mm and 4-repetitiondiffraction patterns ( performed by a He-Ne laser )normally incidentincident at the Bragg angles

Ring gratinglongitudinal viewfar-field diffraction pattern (performed by a He-Ne laser ) inset is the central area of the diffraction pattern Appl. Opt. (2004) , CPL (2004)transverse view

Fabrication of Fresnel zone plateImages of the Peking Univ. logo and picture produced by a Fresnel lens inside fused silica.Microscope image of a Fresnel plate induced in fused silica.

Waveguide

Femtochemistry ---- Nobel Prize 1999The Royal Swedish Academy of Sciences has awarded the 1999 Nobel Prize in Chemistry to Prof. Ahmed H. Zewail ( CIT), for showing that it is possible with rapid laser technique to see how atoms in a molecule move during a chemical reaction.ZewailZewail

New Nobel Prize possibilityFemtobiology Femtomedicine FemtofabricationFemtosecond Intense Field PhysicsFemto.Attophysics ?!

973863211985

THE END Thank You!