D. RytzF.E.E. GmbH, Struthstrasse 2, D-55743 Idar-Oberstein

rytz@fee-io.de

JNCO, Cherbourg (10.06.2013)

Rôle des impuretés dans les cristaux de YAB (YAl3(BO3)4)

Menu

Matériaux NL pour l‘UV : généralités et motivation(s) pour l‘étude du YAB

Propriétés du YAB pour SHG 532/266 nm

Techniques de croissancecristalline

Absorption résiduelles dans l‘UV- Distribution longitudinale, analyses chimiques- Mesures sur poudres cristallines- RPE- Interprétation concernant Fe3+

Comment réduire le taux de Fe3+?

Autres cristaux (KABO, YAG)

Conclusions

NLO materials for UV generation

BBO LBO CLBO BiBO YCOB KBBF YAB

Toxicity --Hygroscopic -- - --Mechanical stability - -- -- ++Hardness - - + - ++

UV transmission + ++ ++ - ++ ?Phase matching cutoff (nm) 410 555 474 580 720 350 492Nonlinear coeff. deff + ++ -Angular acceptance -- +Temp. AcceptanceWalk-off -- -

Damage threshold ++ ++?Thermal dephasing - + - ?Light induced effects - + ? ? ?

Summary of NLO properties

SHG 532/266 nm

Type IAngle(°)

deff

(pm/V)Ang accmradcm

T acc(°C cm)

Walk-off(°)

BBO 47,5 1,1 0,17 5 4,8

CLBO 61,5 0,8 0,49 6,2 1,9

YAB 66,2 0,69 0,41 Approx. 6

1,9

Physical properties of YAB

Structure Trigonal, space group R32 Lattice parameters a = 9.287 A (GAB: 9.34 A; LuAB: -) c = 7.256 A (GAB: 7.31 A; LuAB: -) Density 3. 70 g/cm3 Melting noncongruent Hardness Mohs 7.5 Stability non hygroscopic Specific heat 0.75 W s g-1 K-1 Thermal coductivity 3 – 4 W m-1 K-1 Transmission 160 – 2200 nm Indices no = 1.7553 (GAB: 1,761, at 1064 nm) ne = 1.6869 (GAB: 1,689, at 1064 nm) Uniaxial negative (no > ne)

YAB, a brief history

• YAB = YAl 3(BO3)4

• First: A.A. Ballmann, US Pat. 3‘057‘677 (1962).

• N.I. Leonyuk et al. (1972 and thereafter).

• Self-doubling in NYAB = NdxY1-xAl 3(BO3)4

(L.M. Dorozhkin et al. (1981)).

(RE)AB and YAB in the literature

• Large number of references since 1981 onNd:YAB, Nd:GAB, Yb:YAB.

• Mostly for self-doubling.

• Only limited work on undoped (RE)AB:- US Patent 5‘030‘851 (Filed 1990, expired 1994),

SHG 1064/532 nm.- US Application 2006/0054864

YAB with less than 1000 ppm Mofor generation of < 350 nm.

SHG Angle vs. Fundamental

0,00

10,00

20,00

30,00

40,00

50,00

60,00

70,00

80,00

90,00

0 0,5 1 1,5 2 2,5

Wavelength (µm)

Pha

se m

atch

ing

angl

e (°)

Type I

Type II

YABλ λ/2

D. Rytz et al., Proc. SPIE6998 (2008) 699814-1 .

SHG Nonlinearity

SHG: effective nonlinear coefficients

0,0000,200

0,4000,600

0,8001,000

1,2001,400

1,600

0 0,5 1 1,5 2 2,5

Fundamental wavelength (µm)

NL

coef

ficie

nt (p

m/V

)

Type I (Phi = 0°)

Type II (Phi = 30°)

D. Rytz et al., Proc. SPIE6998 (2008) 699814-1 .

SHG 532/266 nm with YAB

• R. Maillard et al. (2010) θ = 66.2° α = 1.5 – 4.5 cm-1 L = 2.24 mm532 nm: 60 mW/ 60 ns/ 60 kHz/ 0.016 kW/ 45 µmdeff = 0.43 pm/V

• Xuesong Yu et al. (2010) α = 11.2 cm-1

532 nm: 1.54 mJ/ 10 Hz/ 15.4 mW/ 2 GW/cm2

266 nm: 0.24 mJ (15.6%)

• Qiang Liu et al.(2011) θ = 67° α = 0.67 cm-1 L = 6 mm532 nm: 42 W/ 18 ns/ 60 kHz/ 80 µm266 nm: 5.05 W (12.3%)

• H. Liu et al. (2011) θ = 66.2° α = 3.7 cm-1

deff = 1.30 cos θ = 0,56 pm/V

YAB: Transmission

B155/1 (L=0.84 mm)B155/2 (L=1.83 mm)

C291 (L=0.65 mm)E101 (L=1.12 mm)

Li 2WO4 Flux, Air Li 2O-Al2O3-B2O3, Air

YAB: the challenges

• YAB and LuAB are promising materials for UV generation.

• Phase matching conditions known and verified for several wavelengths.

• Challenge: crystal growth of high purity (high UV transmission) material.

• Damage threshold ? Light induced effects?

YAB growth (K2Mo3O10 FLUX)

Crystal E111-2

Cristal: 5.5 gFrom 175 g melt(100 ml crucible)Loss: < 4 g

Duration: 840 h (34 days)Ramp: 0.05 – 0.15°C/h

Growth Pullout1055 1006 °C

Scale: 1 cmc-axis seed

YAB growth (Li2WO4 flux)

Crystal C291-1

Cristal: 7.3 gFrom 175 g melt(100 ml crucible)Loss: < 1 g

Duration: 16 daysRamp:

Growth Pullout998 947 °C

Scale: 1 cmc-axis seed

Menu

Matériaux NL pour l‘UV : généralités et motivation(s) pour l‘étude du YAB

Propriétés du YAB pour SHG 532/266 nm

Techniques de croissancecristalline

Absorption résiduelles dans l‘UV- Distribution longitudinale, analyses chimiques- Mesures sur poudres cristallines- RPE- Interprétation concernant Fe3+

Comment réduire le taux de Fe3+?

Autres cristaux (KABO, YAG)

Conclusions

YAB fluxes (a summary)

Flux Contaminants(typical)

Absorption bands

K2Mo3O10 Mo (100 ppm)Fe (10 – 30 ppm)

245 nm280 nm370 nm420 nm

Li 2WO4 W (80 ppm)Fe (10 ppm)

same

LaB3O6 La (10%)Fe (10 ppm)

same

Li 2O-Al2O3-B2O3 Fe (10 ppm) same

Published tranmission curves for YAB

Yu et al., JCG (2010)

Thickness 0.72 mm Chen et al., AP B (2011)

T = 45% at 266 nm

Alpha = 8 cm-1 Thickness1.0 mm

T = 50% at 266 nm

YAB:B2O3:Li 2O Alpha = 5 cm-1 Liu et al., MRI (2011)

Yb:YAB:Li 2WO4:B2O3 Thickness1.0 mm

T = 58% at 266 nm

Alpha = 3.7 cm-1

YAB:Li 2B4O7:AlBO3

Published tranmission curves for YAB

Yu et al., JCG (2010)

Thickness 0.72 mm Chen et al., AP B (2011)

T = 45% at 266 nm

Alpha = 8 cm-1 Thickness1.0 mm

T = 50% at 266 nm

YAB:B2O3:Li 2O Alpha = 5 cm-1 Liu et al., MRI (2011)

Yb:YAB:Li 2WO4:B2O3 Thickness1.0 mm

T = 58% at 266 nm

Alpha = 3.7 cm-1

YAB:Li 2B4O7:AlBO3

Liu et al., OL (2011)

Alpha = 0.67 cm-1 at 266 nm

YAB:Li 2O:B2O3:AlBO3

YAB: Transmission (sample E128-5/1)

Transmission 800 nm - 185 nm

Blue: seed end

Purple: tail end

E. Recktenwald (FEE – FH Birkenfeld, 2011)

~ 240 nm

~ 300 nm

YAB: chemical analysis (GDMS)

E128-5/3-1 E128-5/3-3

Seed end Tail end

Li (ppm wt) 150 === 160Na 3.9 V 0.40Si 2.7 Λ 5.7K 1.7 V 0.27Ca 6.8 V 3.8Ti 2.4 V 0.83Cr 3.6 V 1.9Fe 10 Λ 46Ni 0.83 === 0.78Zr 1.1 === 0.88Sb 1.5 Λ 2.3Ce 1.3 === 1.4W 360 V 19

Pt < 0.5 < 0.5

Blue: seed end

Purple: tail end

ΛΛΛΛ is symbol for

increase

from seed to tail

Comparison powder / single crystal(M. Jost, M. Weibert, V. Wesemann, FEE, 2011)

0,001

0,0015

0,002

0,0025

0,003

350 370 390 410 430 450

Tran

smis

sion

Wavelength [nm]

KNbO3 single crystal A215-6(normalized signal)

KNbO3 powder

Al2O3 powder, Fe doped

200 250 300 350 400 450 500 550 600 650 700 750 800-0,01

0,04

0,09

0,14

0,19

0,24

Wellenlänge in nm

Tra

nsm

issi

on

in %

200 250 300 350 400 450 500 550 600 650 700 750 800-0,02

0,03

0,08

0,13

0,18

0,23

0,28

Wellenlänge in nm

Tra

nsm

issi

on in

% Nominally pure

100 ppm Fe2O3

1000 ppm Fe2O3

200 250 300 350 400 450 500 550 600 650 700 750 800-0,02

0,03

0,08

0,13

0,18

0,23

0,28

Wellenlänge in nm

Tra

nsm

iss

ion

in %

Al2O3 powder, Fe doped

200 250 300 350 400 450 500 550 600 650 700 750 800-0,01

0,04

0,09

0,14

0,19

0,24

Wellenlänge in nm

Tra

nsm

issi

on

in %

200 250 300 350 400 450 500 550 600 650 700 750 800-0,02

0,03

0,08

0,13

0,18

0,23

0,28

Wellenlänge in nm

Tra

nsm

issi

on in

% Nominally pure

100 ppm Fe2O3

1000 ppm Fe2O3

200 250 300 350 400 450 500 550 600 650 700 750 800-0,02

0,03

0,08

0,13

0,18

0,23

0,28

Wellenlänge in nm

Tra

nsm

iss

ion

in %

Transmission

(arb. units)

Arrow at 266 nm

200 Wavelength (nm) 800

Al2O3 powder, Cr doped

200 250 300 350 400 450 500 550 600 650 700 750 800-0,02

0,03

0,08

0,13

0,18

0,23

0,28

Wellenlänge in nmT

ran

sm

iss

ion

in %

200 250 300 350 400 450 500 550 600 650 700 750 800-0,02

0,03

0,08

0,13

0,18

0,23

0,28

Wellenlänge in nm

Tra

nsm

issi

on in

% Nominally pure

100 ppm Cr2O3

1000 ppm Cr2O3

200 250 300 350 400 450 500 550 600 650 700 750 800-0,02

0,03

0,08

0,13

0,18

0,23

Wellenlänge in nm

Tra

nsm

issio

n in

%

YAB (crystal C300-10, powder, Fe doped)

200 250 300 350 400 450 500 550 600 650 700 750 800-0,02

0,03

0,08

0,13

0,18

0,23

Wellenlänge in nm

Tra

nsm

iss

ion

in %

200 250 300 350 400 450 500 550 600 650 700 750 800-0,02

0,03

0,08

0,13

0,18

0,23

0,28

Wellenlänge in nm

Tra

nsm

iss

ion

in %

150 ppm Fe2O3

Nominally pure

Elektron Spin Resonance (ESR) MeasurementsS. Ilas, P. Loiseau, G. Aka (ENSCP Paris)

• Detection of Fe3+.

• Measurements in starting materials:

• Measurements in molten mass:

Source Charge ESR Fe3+

Al 2O3 SASOL C912007-III No signal < 5 ppm

SASOL C0517094-IV No signal < 5 ppm

Y2O3 TREIBACHER 51/00 No signal < 5 ppm

YARMOUTH 5412 No signal < 5 ppm

Li 2CO3 ALFA AESAR 75097 1000 Gauss1900 Gauss

Broad 10-20 ppm

WO3 ARAN ISLES W-977 1000 Gauss1900 Gauss

Broad, withstructure

10 – 15 ppm

Run Nb. Flux ESR Fe3+

YAB C314-1 Li – Al – B(H2 + N2)

800 Gauss1800 Gauss

Broad > 10 ppm

YAB E135-2 Li – Al – B(N2)

Weakstructure

???

YAB fluxes (a summary)

Flux Contaminants(typical)

Absorption bands Correlation withFe3+

K2Mo3O10 Mo (100 ppm)Fe (10 – 30 ppm)

245 nm280 nm370 nm420 nm

Yes

Li 2WO4 W (80 ppm)Fe (10 ppm)

same Yes

LaB3O6 La (10%)Fe (10 ppm)

same Yes

Li 2O-Al2O3-B2O3 Fe (10 ppm) same Yes

Possible origins of Fe3+ impurities

• Starting materials (oxides, better than 99.99%).

• Pt crucibles (150 ppm Fe is standard).

• Ceramics (> 100 – 500 ppm Fe ?).

• Others?

Oxide powders Fe (ppm)Li2CO3 ALFA 1 For undoped crystals

AI 99.99 3 For doped crystals

AI 99.999 0.75WO3 AI 0.06Y2O3 Treibacher < 5

AI 1 „High purity“Al2O3 SASOL 2 Possibly > 10 ppm

MV Lab 0.5

B2O3 ALFA < 0.2

Ceramics Fe (ppm)Al2O3 FRIATEC 300 - 500 Contains MgO

PLASCERA < 1000ZIRCAR Sali 50 10 ppm Ni, 0 ppm Cr!

ZIRCAR ?Al30 200-240SCHUPPUltra-board 1850

130

SiO2 ROTOSIL 45

Crucibles Fe (ppm)Pt Manufacturer A 150 (Standard)

13 (New)10 (Seed holder)

Oxide powders, ceramics, crucibles:Fe contamination

Fe2+ vs. Fe3+

Fe2+ cannot be incorporated on Al3+ site.Thus: grow crystal under reducing conditions!

Chunlei Liu, Lijuan Liu, Xin Zhang, Lirong Wang, Guiling Wang and ChuangtianChen, J. C ryst. Growth 218 (2011) 618.

Coordination Ionic radius(ppm)

Al 3+ Octahedral 67.5

Fe3+ Octahedral 63-69 < Al3+

Fe2+ Octahedral 75-77 > Al3+

Conclusions et travaux futurs concernant les cristaux de YAB (YAl 3(BO3)4)

• YAB permet de générer > 5W d‘UV à 266 nm.

• Propriétés ONL favorables.

• Croissance de cristaux (50 à 100 g) en cours.

• Réduire la contamination en Fe (priorité no. 1):– purification (matière premières, creusets, céramiques).

– croissance sous atmosphère réductrice.

• Eliminer les mâcles (priorité no. 2):– réduire la densité de mâcles dans le germe.

– favoriser la croissance des facettes prismatiques.

Acknowledgment

V. Wesemann, J. Buchen, W. Scalbert, A. GrossF.E.E. GmbH, Struthstrasse 2, 55743 Idar-Oberstein

S. Ilas, P. Loiseau, G. AkaLab. de Chimie de la Matière Condensée, ENSCP, Paris

F. Balembois1, L. Deyra1, A. Maillard 2, R. Maillard 2, Ph. Villeval3, F. Salin4

1- Lab. Charles Fabry, Institut d‘Optique, Orsay2-LMOPS, Univ. de Metz et Supelec

3-Cristal Laser, Messein4-Eolite, Pessac