worshop : lasinof, june 14th 2010
DESCRIPTION
PATTERNED SECOND HARMONIC GENERATION ON OXIDE GLASSES SURFACE BY THERMAL POLING. Aurélien Delestre , E. Fargin, M. Lahaye (ICMCB, Bordeaux, France ) V. Rodriguez, F. Adamietz, M. Dussauze (ISM, Bordeaux, France ) M.Bellec, A. Royon, L.Canioni (CPMOH, Bordeaux, France ). - PowerPoint PPT PresentationTRANSCRIPT
Worshop : LasINOF, June 14th 2010
Aurélien Delestre, E. Fargin, M. Lahaye (ICMCB, Bordeaux, France)
V. Rodriguez, F. Adamietz, M. Dussauze (ISM, Bordeaux, France)
M.Bellec, A. Royon, L.Canioni (CPMOH, Bordeaux, France)
PATTERNED SECOND HARMONIC GENERATION ON OXIDE GLASSES SURFACE BY THERMAL
POLING
Outline
I / Thermal poling and Second Harmonic Generation (SHG)
II / Silver injection by thermal poling and SHG
- Samples elaboration and preparation for silver injection
- poling voltage and SHG efficiency
- Results and interpretation
III / Efficient structuring of SHG
- Laser ablation, poling
- µSHG patterning measurements
- Results and interpretation
02 /15
T°
Time
High Voltage
T°
Time
High Voltage
Thermal poling for Internal field engraving
03 / 15
AnodeCathode
A
i ~ 0.5 mA
U = 1kV
230°C
G
Negatively charged depletion zone
Na+ cations depletion zone creation (L=3-15 µm)
Mobile cations can migrate from anode to cathode
- ---------
----
-Eint
X
YZ
- - - -- - -Eint
Eint
Embedded internal field induces Second Harmonic Generation in Glasses
int)3()2( .3 Eeff
Glasses are centro-symmetric materials (2)=0
Composition : sodium and niobium borophosphate glasses (BPN42)
(1-x)[0,95NaPO3+0,05Na2B4O7]+xNb2O5 x = 0,42
Silver injection by poling :
Silver layer deposition on the glass surface
Glass samples elaboration + silver injection
04 / 15
Metallic silver film
GlassE
SHG modified ?
Why silver ? Na+ and Ag+ : Comparable diffusion coefficients in oxide glasses
Structuration of silver electrode SHG structuration
~ 5 mm
Poled surface after poling
Zone outside the anode
Zone under the anode
*Référence : M. Dussauze Optics Express, Vol. 13, Issue 11, pp. 4064-4069
Thermal Poling induces - departure of sodium ions
- injection of silver ions
Observation : Efficient poling leads to (2) comparable to the reference
Efficient poling Non efficient Efficient poling
Sample Reference no Ag Ag Ag Ag Ag Ag
Silver thin film thickness (nm)e ±10 nm 0 200 220 170 240 300
2) (pm/V) ± 10-2 1.06 0 0 1.20 1.00 0.96
Nonlinear zone thickness (µm)
L ± 0.1 µm3.0 - - 2.9 3.8 3.0
(2) values deduced from Maker Fringes simulations
05 / 15
Why poling is efficient?
Why poling can be inefficient?
Thermal poling
230 °C, t = 1 h, U ~ 1 kV, i0 = 0.5 mA (sample thickness 1 mm)
0 5 10 15 20 250
2
4
6
8
10
12
14
16
18
20
a
Ato
mic
perc
en
tag
e
Penetration depth under the anode surface (m)
Nb Na P
Sodium depletion zone: 3 µm thickness
Space charge zone identical to SHG efficient zone
*Reference : M. Dussauze Optics Express, Vol. 13, Issue 11, pp. 4064-4069
Reference Without AgNa, Nb, P atomic concentration profiles
Cathode
Anode
Poled zone Poled zone
Quantitative X-ray analysis on the reference
06 / 15
Cations migrations :
- Na+ ions depletion (6 µm)
- Ag+ ions penetration (6 µm)
Quantitative X-ray analysis
07 / 15
Sample efficient poling With Ag
Ag thickness(nm) ±10 nm 170
(2) (pm/V) ± 10-2 1.20
Nonlinear zone thickness (µm) ± 10
-1 2.9
SHG profile correlated to total cations depletion
- between 2.9 µm and 6 µm Ag substitutes to Na
Efficient poling with Ag
- the nonlinear zone producing SHG is located between 0 to 2.9 µm under the surface
efficient SHG zone
Na depletion zone
Ag injection zone
2.90 2 4 6 8 10 12 14 160
2
4
6
8
10
12
14
16
18
20
% A
tom
ic
Depth under the anode surface (µm)
Na Ag P Nb
Atomic concentration profiles under the anode
Cations migration :
- Na+ depletion ( 2 µm)- Ag+ injection ( 2 µm)
*reference : E. Fargin Advanced Materials Research Vols. 39-40 (2008) pp 237-242
déplétion
zone
Quantitative X-ray analysis
08 / 15
Inefficient poling with Ag
Ag+ injection compensatesNa+ depletion
No SHG
0 2 4 6 8 10 120
2
4
6
8
10
12
14
16
% A
tom
ic
Depth under the anode surface (µm)
Na Ag P Nb
Atomic concentration profiles
No space charge zone creation
Poling voltage ~1 kV is the minimum to develop efficient poling
Influence of voltage on poling efficiency
First polings mistake : special attention on the current
Now big care on the voltage !!!Thermal poling
230 °C, t = 1 h, U = different voltage, i0 < 0.6 mA (sample thickness 500µm)
SHG efficiency is linked with poling tension
09 / 15
SHG architecture
Surface profile image of ablated lines
BPN42 + Ag thin film deposition
Laser Ablation of silver lines
(Length = 3 mm, width = 2 µm)
Thermal poling
230 °C, t = 1 h, U = 1 kV, i0 < 0.6 mA
laser Yb :
Wavelength = 1030 nm
pulse duration= 470 fs
Repetition rate = 10 MHz
Mean power = 6 WLa
ser
fs IR
AOM
Lase
r fs
IR
AOM
Lase
r fs
IR
AOM
Lase
r
fs IR
AOM
Lase
r fs
IR
AOM
Lase
r fs
IR
AOM
Ag thin film
Ablated line
100µm
10 / 15
X
YZ
Image of ablated lines (optical microscopy)
Y
X
µSHG Analysis
40
5 µm
-30
-20
-10
0
10
20
30
Length Y (µm)
-40 -20 0 20 40
Length X (µm)
-30
-20
-10
0
10
20
30
-40 -20 200Y (µm)
X (
µm
) Ag Ablated
Poled lines
Ag Non ablated
poled zone
)2(ijk i
kj 2ω (polarization of reflected SHG field)
ω (polarization of incident beam field)
µGSH allows different fields orientations
Different components in )2(
Exemple : YXX )2(
yxx
Ablated lines
X
YZ
11/ 15
zxyzxzzyzzzzzyyzxx
yxyyxzyyzyzzyyyyxx
xxyxxzxyzxzzxyyxxx)2(
Y
X
XXX polarization
SHG signal analysis on the surface
SHG signal is very intense on the lines
non ablated zone
Inte
nsité
(u.
a.)
Nombre d’onde (cm-1)
Ablated zone :600
500
400
300
200
100
0
-500 0 500 1000
Analysis Incident
Surface 3 µm under
the surface
Z=0 Z=1 Z=2 Z=3 Z=4
3D mapping:
12 / 15
zxyzxzzyzzzzzyyzxx
yxyyxzyyzyzzyyyyxx
xxyxxzxyzxzzxyyxxx)2(
0)2( xxx
Z
Wavenumber (cm-1)
Inte
nsité
(u.
a.)
14
12
10
8
6
4
2
0
-500 0 500 1000
Nombre d’onde (cm-1)
Flight intensity
xxx(2) 0
SHG signal for different pump and probe polarizations
New Symmetry induced by poling
13 / 15
Usual symmetry obtained by poling
C∞v
- ---------
----
-Eint
X
YZ
00
0000
00)2(
zzxzzzzyyzxx
yyxyyz
xxzxzzxyyxxx
Cs (symmetry plane: xz)
X
YZ
*reference : A. Delestre, Applied Physics Letters, volume 96, Issue 9, id. 091908(2010)
Quantitative analysis of elements under anode
Silver concentration mapping
14 / 15
Lifted lines
Silver concentration variation through ablated lines
Ablated lines Silver layer
Silver injection
[Ag+] [Ag+][Ag+]
DCXE
X
YZ
DCZE
z
x
Ionic profile in the non ablated area
Ionic profile in the ablated area
Conclusion and perspectives
15 / 15
+ Silver ions introduction by thermal poling :
Silver injection is compatible with SHG
Control the applied voltage (threshold for efficiency)
+ Surface SHG architecture obtained by structured silver deposited electrode:
- creation of new symmetry in nonlinear poled surface
Objective :
Laser ps
532 nm
/2
PrismGlan
Taylor
Laser ps 1064 nm
Power
regulation
µSHG Setup
11 / 23
M1
Platine XYZ
CCD
polarization
Pine hole
/4
M2
M3 M4
M5
M6
M7NIR Objective
Filter 2
Filter Notch1064 ou 532nm
Advantages :
- Mapping (platine XYZ + CCD)
- Résolution ~ 1 µm (Objective NIR 100X, ON = 0,5)
- Simultaneous µRaman spectroscopy
Sample
Présence de signal GSH dans la zone polée
Pas de variation de signal GSH dans la zone ablatée
Y
X
Polarisation YXX
40
-30
-20
-10
0
10
20
30
-40 -20 200
Y (µm)
X (
µm
)
Analyse Incident
1 µm
-5
0
5
10
X (µm)
-4 -2 0 2 4Y (µm)
1.5
1.0
0.5
0.0
Pas de contraste de signal GSH
Signal GSH dans/hors des lignes ablatées
24 / 30
zxyzxzzyzzzzzyyzxx
yxyyxzyyzyzzyyyyxx
xxyxxzxyzxzzxyyxxx)2( 0)2( yxx
6
5
4
3
2
1
0
Intensity (a.u.)
-500 0 500 1000
Wavenumber (cm-1)
Inte
nsité
(u.
a.)
Nombre d’onde (cm-1)
5 µm
-30
-20
-10
0
10
20
30
Y (µm)
-40 -20 0 20 40X (µm)
Echantillon tourné de 90°
Analyse Incident
X
Y
Y (
µm
)X (µm)
Polarisation YYY
Signal GSH homogène
Pas de contraste de signal GSH
50
40
30
20
10
0
Intensité (a.u.)
-500 0 500 1000
Nombre d’onde (cm-1)
Zone ablatée XYY
Signal GSH dans/hors des lignes ablatées
25 / 30
zxyzxzzyzzzzzyyzxx
yxyyxzyyzyzzyyyyxx
xxyxxzxyzxzzxyyxxx)2(
1 µm
-5
0
5
10
Y (µm)
-5 0X (µm)
4
3
2
1
05
Polarisation XYY
Variation de signal GSH
5
4
3
2
1
0
Intensité (u.a.)
-500 0 500 1000
Nombre d’onde (cm-1)
Zone non ablatée XYY
0)2( yyy
0)2( xyy
500
400
300
200
100
0
Intensité (u.a.)
520 530 540 550 560Longueur d’onde (nm)
Les échantillons sont coupés au travers des lignes d’ablation
Polarisation ZZZ
Lignes ablatées
Zone non linéaire
Surface d’analyse
Signal GSH sur la tranche de l’échantillon
100
80
60
40
20
0
Intensité (u.a.)
520 530 540 550 560Longueur d’onde (nm)
Zone non ablatée XZZ
Zone ablatée XZZ 5 µm
-30
-20
-10
0
10
20
30
Z (µm)
-40 -20 0 20 40X (µm)
Y
Z
Analyse Incident
X
YZ
2 µm
-4
-2
0
2
4
6
Z (µm)
-10 -5 0 5 10 15X (µm)
2000
1500
1000
500
0
2 µm
-6
-4
-2
0
2
4
6
Z (µm)
-10 -5 0 5 10 15X (µm)
150
100
50
0
Polarisation XZZ
ONL perpendiculaire aux lignes d’ablation
26 / 30
zxyzxzzyzzzzzyyzxx
yxyyxzyyzyzzyyyyxx
xxyxxzxyzxzzxyyxxx)2(
?)2( zzz
0)2( xzz
µSHG on cross section with a 90° sample rotation
XY
Z
Polarisation XXX Polarisation ZXX
1 µm
-10
0
10
20
X (µm)
-5 0 5 10Z (µm)
200
150
100
50
01 µm
-10
0
10
20
X (µm)
-5 0 5 10Z (µm)
100
80
60
40
20
0
Hypothèse
L’augmentation de GSH dans les lignes ablatées viendrait d’un champ interne perpendiculaire à
ces lignes
DCZE
GSH par polarisation thermique + ablation
Variation de la concentration d’argent au travers des lignes
ablatées
Lignes ablatées
Couche d’argent
Pénétration d’argent
[Ag+
][Ag+
][Ag+
]
Champ interne additionnel perpendiculaire aux lignes
ablatées
Z=0
Polarisation YYY
X
Y
Polarisation YXX
Résultats de µGSH
2 µm
-6
-4
-2
0
2
4
6
Z (µm)
-10 -5 0 5 10 15X (µm)
150
100
50
0
Polarisation d’analyse lignes d’ablation
Variations GSH dans la zone d’ablation
Polarisation XZZdéplétion
Migration des cations depuis l’anode
Création d’une zone de déplétion (L=3-15µm)
anode
Création d’un champ interne
GSH par polarisation thermique
cathode
28 / 30
DCXE
DCZE
X
YZ
0 5 10 15 200
2
4
6
8
10
12
14
16
18
Ato
mic
%
Depth (µm)
lifted unlifted
Sodium + Silver ionic migration profile