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TERAHERTZ SOURCES

By Jean-François ROUX

Université Savoie Mont-Blanc

IMEP-LAHC – UMR CNRS 5130

Le Bourget du Lac- France

1

Outline of the talk

1. Introduction about TeraHertz

2. Direct emission of THz waves

3. Up-conversion of electronic sources

4. Down-conversion of photonic sources

a. Non-linear and electronic mixers

b. CW THz generation using photonics

c. Pulsed THz generation using photonics

5. Conclusion

2

TeraHertz Spectrum1. Introduction

3

Interaction of TeraHertz waves with Matter

• Rotation of molecules

• Bond vibrations

• Stretching and torsion

• Phonons

• Free carrier acceleration

1. Introduction

4

Fig. 1. The rotational spectrum of the Orion nebula, showing spectral

fingerprints of diatomic and polyatomic molecules present in the interstellar

cloud. (Adapted from G.A. Blake et al., Astrophys. J. 315, 621 (1987).)

THz spectroscopy in Astrophysics

1. Introduction

5

THz spectroscopy of Gases

1. Introduction

6

Analysis of the terahertz spectra from a sample of diclofenac acid

can readily distinguish between the two chief forms, or polymorphs,

of the drug. Courtesy of Analytical Chemistry.

Terahertz Techniques Reveal the Hidden World of Pharmaceuticals

THz spectroscopy of Pharmaceutics

1. Introduction

7

8

Spectroscopy of Crystals

CollaborationH. Minamide (Riken, Sendaï) et B.Boulanger, P. Segonds, C. Bernerd, I. Louis Néel

phonon TO at 8.06 THz

phonon LO at 8.76 THz

Cristal DAST CdTe NaCl InSb ZnTe GaSe ZnSe GaAs InP ZnO

fphonon(THz) 1.13 4.20 4.92 5.21 5.31 6.33 6.45 8.00 9.12 12.41

Spectroscopy of Phonons

phonon TO at 5.3 THz

phonon LO at 6.2 THz

ZnTe GaAs

Temporal trace of THz signal as emitted by a GaAs photoswitch and detected by in ZnTe crystal.

FFT

1. Introduction

9

0 5 10 15 20 25

-3

-2

-1

0

z

HH

thic

kn

ess (

mm

)

distance (mm)

T

Courtesy of JC. Delagnes, Bordeaux

THz imaging

1. Introduction

10

THz imaging applicationsMedecine

Art Conservation

1. Introduction

11

ANR-JST WS 2012 of 29 14 March 2012

Local Oscillator

LO

Opt. Carrier 1

Opt. Carrie 2PDIM

Data

RF IFData

IM: Intensity

Modulator

Receiver Transmitter

THz communications Technology1. Introduction

ANR-JST WS 2012 of 29 14 March 2012

1. Introduction

Which sources for THz studies ?

Tape ?

Or Free Electron laser ?

Which sources ? The THz “Gap”

1. Introduction

14

Up- conversion Down- conversion

Direct THz Emission

Different ways of generating THz

1. Introduction

15

Direct emission of THz signal

Blackbody radiation

Electron’s beam sources

Backward Waveguide Oscillators

Synchrotron

Gas Laser

Quantum Cascade Laser

2. Direct THz emission

16

Blackbodies

10-12

10-10

10-8

10-6

10-4

10-2

100

102

104

10-1

100

101

102

103

300 K

373 K

473 K

1273 K

5800 K

Spec

tral

den

sity

(W

/cm

2/µ

m)

Wavelength (µm)

Temperature

THz rangev

isib

le

Mercury lamps, high-temperature ceramic resistors…

Blackbody radiation


17

Rayleigh-Jeans:Radiation by 1 cm2 of BB (T=300 K) integrated in the range 0.1-10 THz ≈ 1 nW.

Mercury lamps, high-temperature ceramic resistors… Lamps: Radiation by the discharge (104 K) and by the bulb envelop (103

K)(quartz)

Typically, a 75-100 W lamp radiates a broadband signal (0.1~20 THz)

with a spectral power density of a few 10's of µW per THz.

Incoherent radiation

Blackbody sources


18

0 0.4 0.8 1.2 1.6f THz1 µW

10

100

1 mW

10

100

“Tube Technology”Backward wave oscillators


19

e- (v) THz

THz

Electron Gun

• Based on the Smith-Purcell effect

Synchrotron Radiation

E= 2.75 GeV

2/ = 0.37 mrad

Continuous energy distribution in the radiation emission cone

High energy photons emitted with a smaller angle than low energy

photons

Courtesy of Olivier Pirali, AILES Beamline at Soleil, Orsay


20

“ incoherent” : Intensity of THz linear with ring current

“cohérent” : ITHz linear with the square of the ring current

500

400

300

200

100

0

Inte

nsit

y (a

.u.)

1.51.00.50.0

Frequency (THz)

6050403020100

Wavenumbers (cm-1

)

Coherent Beam Short bunch : 3mA - 3ps Long bunch : 180mA

Synchrotron Radiation and Coherent Synchrotron Radiation

Courtesy of Olivier Pirali, AILES Beamline at Soleil, Orsay


21

Molecular lasers

rotation energy levels in gases

J=12J=11J=10J=9

496 µm

541

595

J=14J=13J=12J=11

419 µm

452

CO2

laser pump

n=1 n=3n=2

From Edinburgh Instruments


22

THz Quantum-Cascade Lasers

QCL

1 mW average power in the 1.8 – 5 THz range

20 mW pulsed power

20 000 $ (QCL) + 100 000 $ (cryo-cooler)


23

Quantum Cascade Lasers

CASCADE scheme : N periods = N photons per electron

Resonant tunneling

e-

Multiple periods + Electric field -> resonant tunneling

CB

En

erg

y

3

21

Intersubband transitionWaveguide

Active region

From Sarah Houver et al. Journées THz 2015

Quantum cascade lasers2. Direct THz emission

24

Quantum Cascade Lasers

From A. Tredicucci Winter school on THz, Trento 2011.

0

100

200

300

400

2 5 10 20

Tem

pera

ture

(K

)

III-V compoundsphonon bands

LN2

Peltier

Atmospheric windows

500

Wavelength (m)

50 100

GaAs based lasers

InP based lasers

200

Sb based lasers

THz QCL's (f> 3 THz)


25M. Belkin, F. Capasso .Phys. Scripta 90, 118002 (2015)

3*fosc

h3 Oscillator

Fund=foscN*fosc

x N

Fund= fosc GHz

Harmonic Oscillators Multiplier chains

THz emission by up-conversion of

mm signals

From Hani Sherry, ST Microelectronics, Journées THz 2015.


26

THz emission by High Order RF Oscillator

• Oscillates at a fundamental of 120GHz

• 5th Harmonic 600GHz signal extracted and radiated

600GHz 5-push Oscillator in 65nm CMOS bulk

From Hani Sherry, ST Microelectronics, Journées THz 2015.

10 µW at 600 GHz

Potentially 1 mW at 300 GHz


27

Solid-state Sources : power vs frequency


28

Down Conversion of Photonic sources

Converting optical beams into THz beams

Needed : an optical source (laser) + a nonlinear device

Pulsed (fs) and CW operations

Advantages : using efficient laser sources and smart

optical technologies

Disadvantages : frequency conversion = loss of efficiency


29

From Optics down to THz: case of CW

regime

2.5 THz

TERAHERTZ

400 fs

2.5 THz

INFRA-RED

400 fs

1. Introduction

30

FFT

FFT-1

Down Conversion

1530 1550 nm

Usually low peak power to down-convert

Tunability or Narrowband

330 fs ~ 1 THz

TERAHERTZ

330 fs

~ 2 THz

INFRA-RED

1. Introduction

31

FFT

FFT-1

Down Conversion

From Optics down to THz: case of CW

regime

Potentially high peak power to down-convert

Broadband effect

Pulsed lasers for THz pulse generation


32

Diode

Absorbant

Saturable

Lames

d’ondeRotateur de

FaradaySortie

Coupleur

Fibre dopée

erbium

Mirroir

Commercial systems

• from 800 to 2200 nm

• from 12 to 150 fs

• from 1 kHz to 100 MHz rep. Rate

• from nJ to mJ per pulse

Dedicated dual-wavelength lasers for THz CW generation

Laser1 : w1

Laser2 : w2THz at w1-w2

THz emitter

• Classical cw THz generation by optical beating of two lasers

• Easy to perform

• Tunable

• Reduced frequency stability

• CW THz generation using dual-wavelength laser

Laser1 : w1 AND w2

THz at w1-w2

THz emitter

• Stable

• Compact

• Tunable ?


33

Dual-wavelength lasers for THz generation

• Large panel of possibilities: solid-state lasers, semiconductor laser, fiber lasers…

• CW or Q:switch regime

• Central wavelength has to match THz emitter technology

• Gain competition in between different laser modes

1063 nm

1063 nm

1065 nm

1065 nm

Example : gain competition in Nd:GdVO4

The modes lasing at

the less efficiently

pumped wavelength

are « killed »


34

2-color laser passively Q:switch


• Beating in between two lasing transitions of two different crystals placed in 1 cavity

LC1 LC2SA

Dual wavelength emission Poor pulses synchronization

due to bleaching competition

in the saturable absorber

LC1 : Nd:GdVO4

LC2 : Nd:YVO4

35

2-color laser externally triggered

30 ns pulse duration

70 W peak power

100 % synchronizat°

• Beating in between two lasing transitions of two different crystal placed in 1 cavity

36


2-color Yb:CaF2 laser (Thalès)

• Beating in between two different longitudinal modes of the same lasing transition

2 THz tunability

THz generation in a LT-InGaAs PSW

Figures from Daniel Dolfi, Thalès, France


37

High Purity THz generation usingBrillouin Fiber lasers (IEMN)

Circulat

orEDFA

-1000 -500 0 500 1000-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10

ESA (316 GHz)

SNR = 65 dB

Rela

tive p

ow

er

(dB

)

Offset frequency (kHz)

BFL 1.7 GHz

BFL 316 GHz

ESA Phase noiseSNR = 75 dB

G. Ducournau et al., Optics Letters 36, 2044 (2011) Photomixing at 316 GHz:

DFB Laser FWHM: 1 MHz

Brillouin Fiber Laser: 1kHz 38

2-color VCSEL based on transversal modes selection (IES)

• Half GaAs based VCSEL with sub- l absorbing mask to select 2 transversal modes

39

1.418 THz

330 GHz

Presented at 3rd European Worshop on VCESEL, Motpellier, November 2015

The device shows stable 2 color operation.

200 GHz radidation has been demonstrating

using ultrafast photodiode

Optical mixers for Down Conversion of Photonic sources


40

ve(t) vs(t)RC

Diode

• Amplitude demodulation in Radio = frequency down-conversion

Resonant nonlinear

phenomena

Non-resonant nonlinear

phenomena

Electron/ holes pair

generation by absorption in

an opaque media

Difference frequency

generation in a transparent

nonlinear media

Which nonlinear element sensitive to optical frequencies ?

Optical absorption in semiconductorsreminder

h+

VB

CB

e-

hn

band-to-band

absorption

Ge

In0.53Ga0.47As

Si

InP

GaAslog a

(cm

-1)

0.6 1.8

1

4

1.20.8 1.0 1.4 1.6 l (µm)

2

3

Visible Range GaAs absorbs 10 times more than Si

NIR Range : Onlmy InGaAs or Ge can be used


41

Principle of Ultrafast photoswitches

laser

)(tJ

Vcc

• Simple, Planar,

• No internal Field

• Lifetime and RC limited

• Low Capacitance

• Low Quantum Efficiency


42

Vcc

Zc

ZLr(t)

RDark

C

1

exp

e h

c

Wg t q N t P t

r t L

tN t Nphot

C few pF

a

• Optically controled resistor with lifetime limited response

0

0.2

0.4

0.6

0.8

1

-1 0 1 2 3 4

R

(A

.U.)

delay ps

126 fs e- lifetime

2 ps hole lifetime

LT-GaAs annealed

J. F. Roux et al., :

3rd symposium on Non-Stochiometric III-V

compounds, Erlangen, Germany, 8-10 October 2001

Low Temperature Grown GaAs

0

0.5

1

1.5

2

2.5

3

3.5

300 400 500 600 700 800

Tem

ps

de d

écro

issa

nce (

ps)

Température de recuit (° C)

Be concentration

3 1017

cm-3

PL

5 1018

cm-3

PL

2 1019

cm-3

PL

3 1017

cm-3

R

5 1018

cm-3

R

Molecular Beam Epitaxy @ 200~300°C

With Excess of As and Be doping


43

CW photoconducting emission with interdigitated LTG-GaAs structures

Appl. Phys. Lett., vol. 66, p. 285 (1995)

1 2

2 21 1

270

210

0.01

100

rad

L c

c

L

Rad

opt

PPP

R C

fs

R C fs

P mW

P mW

w w

Low efficiency !


44

Beating of 2 Ti:Sa CW lasers

Broadband spiral antenna

2-laser diodes CW THz systems

Commercial equipment, Germany)

Wavelength

range*853 + 855 nm 1546 + 1550 nm

Lasers 2x DL DFB TeraBeam 1550

Laser power

(fiber output)2 x 50 mW 2 x 30 mW

Scan range

per diode± 1.3 nm ± 2.2 nm

Frequency

accuracy2 GHz absolute , 10 MHz relative

THz scan

range

Typ. 0 – 1800

GHzTyp. 0 – 1200 GHz

Optical

isolation

60 dB per

laser80 dB per laser


45

100 GHz InGaAs Waveguide Photodiode

InGaAs :

Absorption : 7000 cm-1 @1550 nm

Vsat=6.5 106 cm/s

Selected Topics in Quantum Electronics, IEEE Journal of , vol.16, no.5,

pp.1099-1112, Sept.-Oct. 2010


46

• PIN waveguide photodiode with transit time limited response

WITH

UTC-PD as THz sources

e-

h+

p

Contact

InP

Sub-

Coll.

(n)

InP

Coll.

(i)

Graded

absorbing

layer

100 nm

137 nm

InGaAs

(p)

UTC-PD

TEM wideband

Horn Antenna

20 µm

Barrier


47

• Uni-Travelling Carrier photodiode with transit time limited response

Electrons moves

faster than holes

so let’s reduce

hole’s contribution !

400 800 1200 1600 200010

-2

10-1

100

101

THz power + Diffused 1.55 µm

Diffused 1.55 µm level

UTC Model

UTC 2 µm

Optimisé 1040 GHz

APC 23 dBm (Extrapolé de 23,5)

-0,4 V

Bolo Si

Atten Elec 20 dB

(Prise en compte) i UTC ajustés

pour les deux courbes

TH

z d

ete

cte

d p

ow

er

(µW

)

Frequency (GHz)

• Max power: few µW @ 1 THz

• Power at 300 GHz: from 10 to 1000 µW

CW THz emission using photodetectors

• Low Optical to THz power conversion

• Thermal breakdown if Popt > 100 mW

• THz power vs frequency


48

laser

( )( )THz

d J tE t

dt

)(tJ

Vcc

Dynamics vs carrier lifetime

from Duvillaret et al. JSTQE 2001

• Ultrashort laser pulse + LTG-GaAs Photoswitch broadband THz generation

Dynamics vs laser pulsewidth

Pulsed THz emission with LTG-GaAsphotoconductors


49

Typical THz signal radiated by a photoswitch

-80

-70

-60

-50

-40

-30

-20

-10

0

0 1 2 3 4 5 6

4 THz signal

Sp

ectr

al p

ow

er a

mp

litu

de

(dB

)

Frequency (THz)

20/12/00

2 µW at 82 MHz rep rate

0 5 10 15 20 25 30 35-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

Curr

ent (n

A)

Time (ps)

~ time-derivative

of a ps pulse

H2O lines

• Photoconductive emission using a femtosecond Ti:Sa Oscillator (100 MHz, 500 mW)


50

-70

-60

-50

-40

-30

-20

-10

0

0 1 2 3 4 5

FIE

LD

AM

PLIT

UD

E (

dB

)

FREQUENCY (THz)

20x20 µm2

45 µm

35 µm

40 µm

5 µm 5 µm

0

100

200

300

400

500

0 10 20 30 40 50

100 mW

44.4mW

16.2 mW

4 mW

AV

ER

AG

E R

AD

IAT

ED

TH

z P

OW

ER

(n

W)

VOLTAGE (V)

Electrical

Breakdown

V2.5

V2.5

V2.3

V1.8

P(THz) varies with Vbias2 and Popt

2

GaAs BT: Be

ElectrodesFrequency domain

Pulsed THz emission with dipole antenna PSW

PTHz= 10 µW broadband

Cost = 1500 €


• Photoconductive emission using optimized dipole antenna

51

52


THz Time Domain Spectroscopy Systems based on pulsed THz generation in photoswitches

THz power = 3.8 mW

Popt = 240 mW

Conversion

efficiency = 1.5 %

3.8 mW of Pulsed THz emission with interdigitated plasmonic electrodes

The coupling to Surface plasmon enhances the optical

absorption under the electrode where Ebias is the larger

Yardimci, N.T.; Shang-Hua Yang; Berry, C.W.; Jarrahi, M., "High-Power Terahertz Generation Using Large-Area Plasmonic Photoconductive Emitters,"

in Terahertz Science and Technology, IEEE Transactions on , vol.5, no.2, pp.223-229, March 2015

• Increase of photoconductors efficiency by optimizing the photogeneration of e-


53

Towards high THz power generation

using amplified pulsed lasers

850 µJ/pulse (150 fs)

Rep. Rate = 1 kHz

3 X 3 cm2 GaAs

photoswitch biased

at 1 kV/cm

Max THz field = 10 kV/cm

THz emission by photoconductiove saturates at high

optical power due to bias field screening etc… From Loefler et al. Optics Express 2005.

Photocon.

DFG in ZnTe


• Use of large area photoconductive structures to absorb large amount of photons

54


55

Non-linear Optics : second order effects

PNL generaly supposed to be very weak…

(1) (2) 2 (3) 3

0 0 ...P E E E

2 2 2

02 2 2 2

1E E P

z c t t

With

56

2 21 1 21

1 1( )

2 2exp( xp( )) eA i t ik z c A i t iE k zt c ccww

2

2 2

1

2

2 2 2

1 2 1 2 1

*

1 2 1

2

1 1 1

2

2

2

1 2

( )

exp(2

2 exp ( )

2 exp (

(

2

)

exp(2 2

( )

2

)

2

)

)

A i t ik z c

A A i t i

A i t

E t

A A

ik

A A i t i

z cc

k

c

k k t c

k cc

c

t

w

w

w

w

w

w

The non-linear polarization is proportionnal to :

• Consider the interaction between 2 waves at w1 et w2 in a non-linear (2) media

2nd-harmonic gen

2nd-harmonic gen

Sum-freq gen

Difference-freq. generat°

Rectificat°


2 22

2 20, 1 2( ) sinc ( / 2)

2 effsig z

sigsig

c LP L d PP k L

n

lw

• Interaction length >> lTHz

• High non-linear coefficient

• High optical input peak powers

• Low THz refractive index

57

THz Generation by DFG

L

I

k large

k small

• Low THz losses

• Low Group Velocity Dispersion (for

Pulsed generation)

• Low phase Mismatch


kpol=k1-k2k2

k1

kTHz=n(wTHz). wTHz/c

pol sigk k k

Phase Mismatch

58

2.28 i=1

1.13 i=2

1.50 i=3

0,71

2,161,22~ 6008,0

2,9

no=2,46

ne=1,70

r11= 77DAST

2,685,4~ 109 1,2 =11

3 =15

ne=1,866r33= 36,3

r23= 15,7

KTP

4,5 1,71

1,82

14,2~ 110 1,2 =43

3 =28

no=2,286

ne=2,200

r33= 30,9

r51= 32,6

LiNbO3

6,23 2,01

7,27

14,1~ 85 1,2 =41

1,2 =43

no=2,176

ne=2,180

r33= 30,5

r13= 8,4

LiTaO3

5,36,751,1~ 45 =10,1n=2,853r41= 4,04ZnTe

(THz)(kV)(ps/mm)(pm/V)(pm/V)

phonon

fTO

EOS

Vp

GVDfigure of

merit(rectification)

DC

dielectric

constant

refractive

index

EO

coefficient

crystal

Figure of Merit of usual non-linear

crystals for DFG

Choice of the crystal depends on the application… and on the source


Quasi-Phase Matching in periodic

structures

nopt and nTHz are usually different

nopt nTHz

ZnTe 2.85 3.16

LiNbO3 no=2,28

ne=2,2

n=6.4

n=5.3

DAST no=2,46

ne=1,70

no=2,82

ne=1,70

k=k1-k2-kTHz-2p/L

2

THz gr

opt THz

c

n n

pw

L

Intermodal phase matching in

waveguides

nTHz

nopt

Phase matching in birefringent

crystals

59

How to achieve Phase Matching ?


FOM taking into acount THz losses

7 ps ; 50 MHz

1 µW av.

60

Pulsed THz generation by DFG in waveguide

Optical terahertz wave generation in a planar GaAs waveguide, by K. Vodopyanovand Yu. H. Avetisyan, Opt. Lett. 33, 2314-2316 (2008)


Quasi CW THz generation by DFG in GaSe

Lasers Q:Switch. Pulse

width = 20 ns, 40 kHz

PTHz = P2opt

0.5 mW peak1 kW peak61W. Shi et al. Optics Letters Vol32. 2007.

• DFG at 1.5 THz in GaSe pumped by Q:switched fiber laser : Type II interaction


k=k1-k2-kTHz-2p/L

2

sinTHz gr

opt THz

c

n n

pw

L

Femtosecond

broadband excitation

« CW » THz signal

Losses in LiNbO3 attenuates the THz signal 62

THz generation in PPLN


Microchip

Nd:YAG laser

Pumping beam

MgO:LiNbO3

Terahertz wave

Calibrated Pyroelectric detector

kp

Si-prism700 µJ/pulse,

420 ps, 100 Hz

ECDL + Amp.Seeding beamCW, 500 mW

Phase matching condition

l / 4

Diode-pumped Nd:YAG amplifier

PBS

x

y

z

Grating

3f = 600

mm

f = 200

mm

• Schematic of high-power tunable THz-wave parametric generator (is-

TPG) pumped by micro-chip YAG laser

63

Compact THz Parametric Generator (injection seeded)


Courtesy of Dr . Minamide and Dr. C. Otani. Riken Sendaï.

Max THz power : 140 W peak at 1.8 THz

Commercial THz OPO

64

Towards high THz power generation

using amplified pulsed lasers

850 µJ/pulse (150 fs)

Rep. Rate = 1 kHz

Max THz field = 10 kV/cm

DFG in ZnTe = possible high

intensity generationFrom Loefler et al. Optics Express 2005.

DFG in ZnTe


• Use of DFG in large area nonlinear crystal (ZnTe) as emitter

65

Slope = 1

Slope = 2

66

Intense THz generation in LiNbO3

LiNbO3 shows one of the best FOM for

THz generation but high refractive

indexes mismatch leads to complicated

phase matching schemes


• Optical Tilted wavefront for phase matched DFG in LN

67

1 µJ

1 mJ

d’après Fülos OTST 2013

ETHz > 100 kV/cm

• Studies in non-linear THz physics:

Kerr effect, Self Phase Modulat°

THz optical rectification, SHG

• High THz/ Matter interaction in

resonant structures


Intense THz generation

• Generation of THz fields larger than 100 kV/cm

68

Time Resolved Nonlinear THz spectroscopy of GaAs

AbsorptionSaturation THz in n:GaAs (Hoffmann 2009)

a vs ETHz Frequency domain Time domain


69

Enhancement of THz Field in resonant EM

structures : towards MV/cm

• THz Absorption Saturation in VO2 (M. Liu et al. Nature 2012)

Champ E x 30 => 3 MV/cm

High nonlinearity of the devices


Ultra-broadband THz/mid-IR pulses: THz „white light“

GenerationDetection

Thomson et al, Opt. Express 18, 23173 (2010)70


• Use of THz generation in plasma to cover the 10-140 THz bandwidth

THz sources

71

CONCLUSION

THz sources: who is the winner ?

72

CW sources below 600 GHz: Transistors based oscillators are Ultra-compact, Powerful,

Versatile, CMOS Integrated, Low-Cost (?)

above 4 THz: Quantum Cascade Lasers are working at « Room Temperature »

(quasi), Ultra-compact, Powerful, Efficient

fr. 0.6 to 4 THz: Down Conversion of Photonic Sources offers large panel of

possibilities such as tunability, narrow linewidth, CW or pulsed

regime etc…

Broadband sourcesincoherent: Blackbody radiation is popular, low cost, reliable

coherent: Down conversion of fs pulses offers ultrastable THz pulses, large

measurments dynamics, versatile, open the way to new field of THz

physics

Acknowledgements

• Jean Louis Coutaz, Frédéric Garet, Gwenaël Gaborit, Emilie Hérault, Maxime

Bernier, Guy Vitrant and Florent Pallas from IMEP-LAHC

• Jean-François Lampin and Guillaume Ducourneau from IEMN, Lille

• Stéphane Blin and Arnaud Garnache from IES, Montpellier

• Antoine Kervorkian and Grégoire Souhaité from Teem Photonics

• Daniel Dolfi from Thalès

• H. Minamide and C. Otani from Riken Institute, Japan

• Hanny Sherry from ST Microelectronics

• Olivier Pirali from Ailes Beamline at Soleil, Orsay

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Thank you for your attention,

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