Daniel Rytz, Andreas Gross, Sophie Vernay, Volker Wesemann

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

Remerciements:

X. Pétrissans, J. Lejay, L. Georghe, P. Loiseau, G. Aka

Lab. de Chimie de la Matière Condensée, UMR 7574, ENSCP

P. Georges1, A. Maillard2, Ph. Villeval3, L. McDonagh4, F. Salin4

1- Lab. Charles Fabry, Institut d‘Optique

2-LMOPS, CNRS-UMR 7132, Univ. de Metz et Supelec

3-Cristal Laser

4-Eolite

CMDO 24.11.08

CRISTAUX DE YAB = YAl3(BO3)4 POUR

CONVERSION DE FREQUENCE DANS L’UV

PLAN

• Cristaux non linéaires pour l‘UV.

• Limites des cristaux existants

THG 355 nm, SHG 266 nm.

• Propriétés du YAB:

– SHG, THG, SFG.

– Etat de l‘art et perspectives.

Pump Nd:YAG SHG THG UV output

808 nm 1064 nm 532 nm 355 nm

NLO CRYSTALS FOR UV (340-360 nm)

Pump Yb:Y2O3 SHG THG UV output

946 nm 1030 nm 515 nm 343 nm

Pump Pr:YLF SHG

405 nm 720 nm 360 nm

Pump Nd:YAG SHG SHG UV output

808 nm 1064 nm 532 nm 266 nm

NLO CRYSTALS FOR UV (250-270 nm)

Pump Yb:Y2O3 SHG SHG UV output

946 nm 1030 nm 515 nm 257 nm

Pump Pr:YLF SHG

405 nm 510 nm 255 nm

NEW NL MATERIAL

FOR UV GENERATION

• Motivation:

generation of wavelengths < 450 nm.

• Wanted:

0,326 – 0,366 µm (HG of Nd3+, Yb3+).

0,245 – 0,275 µm (HG of Nd3+, Yb3+).

0,245 – 0,365 µm (HG of Pr3+).

• State of the art presently limited to very few NL

materials.

MATERIALS FOR SFG 355 nm

1,10,523,133,7BiBO

8-103,3

2,1

0,9

0,4

58,7

73,2

YCOB

63,83,150,80,6842,737LBO

13160,350,261,42,053931BBO

II

T acc

(°C cm)

I

T acc

(°C cm)

II

Ang acc

mradcm

I

Ang acc

mradcm

II

deff

(pm/V)

I

deff

(pm/V)

Type II

angle

Type I

angle

1064 nm 532 nm 355 nm

MATERIALS FOR SHG 266 nm

3,20,430,6136,2KBBF

KBe2BO3F2

2,50,340,2655KABO

K2Al2B2O7

1,96,20,490,861,5CLBO

CsLiB6O10

4,850,171,147,5BBO

BaB2O4

Walk-off

(°)

T acc

(°C cm)

Ang acc

mradcm

deff

(pm/V)

Type I

angle

532 nm 266 nm

LIMITATIONS

• BBO - hygroscopic.

- angular acceptance and walk-off.

• LBO - hygroscopic.

- SHG only for > 555 nm.

• YCOB - limited deff.

- SHG only for > 720 nm.

LIMITATIONS (Cont‘d)

• CLBO - strongly hygroscopic.

• BiBO - absorption below 290 nm.

• KBBF - contains Beryllium.

NL MATERIALS FOR UV

There is a need to find a material with a

favorable set of properties:

- not hygroscopic.

- non toxic.

- phase matchable with acceptable deff.

- low losses.

- high damage threshold.

Trigonal

Hardness 7.5 mohs

Not hygroscopic

Thermal conductivity 3 - 4 W m-1 K-1

Transmissive 160 – 2200 nm

Where is UV cutoff in transmission?

NEW UV MATERIAL (PROPOSED: JULY 2007)

(RE)Al3(BO3)4 (with RE=rare earth),

YAB = YAl3(BO3)4,

LuAB = LuAl3(BO3)4,

YbAB = YbAl3(BO3)4,

GAB = GdAl3(BO3)4.

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)

Ph

ase m

atc

hin

g a

ng

le (

°)

Type I

Type II

λ λ/2

SHG Nonlinearity

SHG: effective nonlinear coefficients

0,000

0,200

0,400

0,600

0,800

1,000

1,200

1,400

1,600

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

Fundamental wavelength (µm)

NL

co

eff

icie

nt

(pm

/V)

Type I (Phi = 0°)

Type II (Phi = 30°)

SHG Parameters

Tab. 5 SHG Typ I Typ II Typ I Typ II Typ I Typ II Typ I

Phi = 0° Phi=30°

Winkel-

akzeptanz

Winkel-

akzeptanz

Walk-

off

Lambda Lambda/2 Winkel Winkel deff deff mrad cm mrad cm °

µm µm ° ° pm/V pm/V

0,492 0,246 85,4 0,14 1,76 0,42

0,502 0,251 77,1 0,38 0,66 1,13

0,532 0,266 66,2 0,69 0,41 1,91

0,622 0,311 51,1 1,07 0,36 2,52

0,742 0,371 41,2 65,6 1,28 0,29 0,43 1,09 2,54

0,802 0,401 38,1 58,3 1,34 0,47 0,47 0,99 2,48

0,912 0,456 34,0 50,3 1,41 0,69 0,56 1,03 2,36

THG Angle vs. Wavelength

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)

Ph

ase m

atc

hin

g a

ng

le (

°)

Type I

Type II

λ and λ/2 λ/3

THG Nonlinearity

THG: effective nonlinear coefficients

0,000

0,200

0,400

0,600

0,800

1,000

1,200

1,400

1,600

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

Fundamental wavelength (µm)

NL

co

eff

icie

nt

(pm

/V)

Type I (Phi = 0°)

Type II (Phi = 30°)

THG Parameters

THG Typ I Typ II Typ I Typ II Typ I Typ II

Phi=0

°

Phi=30

°

Winkel-

akzeptanz

Winkel-

akzeptanz

Lambda 1 Lambda 2 Lambda 3 Winkel Winkel deff deff

µm µm µm ° ° pm/V pm/V mrad cm mrad cm

0,710 0,355 0,237 79,8 0,30 0,74

0,810 0,405 0,270 58,4 0,89 0,33

0,950 0,475 0,317 46,5 60,3 1,17 0,42 0,35 0,58

1,030 0,515 0,343 42,3 53,6 1,26 0,60 0,38 0,57

1,060 0,530 0,353 41,0 51,6 1,28 0,66 0,40 0,58

1,340 0,670 0,447 33,2 40,7 1,42 0,98 0,55 0,72

SFG Parameters

SFG Typ I Typ II Typ II Typ I Typ II Typ I Typ II

ooe eoe

oee

Phi=0

° Phi=30°

Winkel-

akzeptanz

Winkel-

akzeptanz

Lambda 1 Lambda 2 Lambda 3 Winkel Winkel Winkel deff deff

µm µm µm ° ° ° pm/V pm/V mrad cm mrad cm

1,344 0,881 0,532 30,5 39,2 51,7 1,47 1,02 0,70 0,98-1,55

1,554 0,809 0,532 30,2 36,8 57,0 1,47 1,09 0,70 0,91-1,92

0,810 0,632 0,355 42,9 62,6 1,25 0,36 0,40 0,85

1,064 0,532 0,355 40,8 51,5 1,29 0,66 0,40 0,59

0,642 0,454 0,266 64,5 0,73 0,38

0,722 0,421 0,266 62,2 0,79 0,35

0,812 0,396 0,266 59,6 0,86 0,33

0,982 0,365 0,266 55,1 70,0 0,97 0,20 0,31 0,59

1,062 0,355 0,266 53,3 64,9 1,02 0,31 0,30 0,48

1,342 0,332 0,266 48,0 54,4 1,14 0,58 0,28 0,36

SFG Parameters (cont‘d)

SFG Typ I Typ II Typ II Typ I Typ II Typ I Typ II

ooe eoe

oee

Phi=0

° Phi=30°

Winkel-

akzeptanz

Winkel-

akzeptanz

Lambda 1 Lambda 2 Lambda 3 Winkel Winkel Winkel deff deff

µm µm µm ° ° ° pm/V pm/V mrad cm mrad cm

1,064 0,266 0,213 72,1 0,52 0,37

1,326 0,254 0,213 61,5 69,9 0,81 0,20 0,26 0,38

0,720 0,355 0,238 77,8 0,36 0,62

0,720 0,520 0,302 52,4 1,04 0,35

0,910 0,720 0,402 37,7 53,0 64,2 1,35 0,62 0,47 0,82-1,29

0,910 0,808 0,428 35,8 51,5 56,3 1,38 0,66 0,51 0,91-1,09

1,064 0,532 0,355 40,8 51,4 1,29 0,66 0,40 0,59

1,062 0,589 0,379 38,7 49,5 1,33 0,72 0,43 0,65-1,35

1,062 0,751 0,440 34,6 46,2 59,5 1,40 0,81 0,53 0,82-1,26

1,062 0,808 0,459 33,6 45,6 55,2 1,42 0,83 0,56 0,89-1,72

1,338 0,749 0,480 32,0 39,9 59,7 1,44 1,00 0,61 0,83-1,21

1,338 0,806 0,503 31,2 39,5 55,6 1,45 1,01 0,65 0,89

SFG or OPO Angles

SFG OR OPO WITH 355 nm PUMP

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)

Ph

ase m

atc

hin

g a

ng

le (

°)

ooe

eoe

ooe

eoe

oee

oee

PROPERTIES OF (RE)ABStructure 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)

(RE)AB AND YAB IN THE

LITERATURE

• Large number of references on

Nd:YAB

Nd:GAB

Yb:YAB

since 1981.

• Mostly for self-doubling.

• Only limited work on undoped (RE)AB.

PAST WORK ON UNDOPED

(RE)AB

US Patent 5‘030‘851

(Filed 1990, expired 1994)

YAB (without Nd) as a NLO crystal.

SHG 1064/532 nm Type I reported.

Angle =33° from z to x in xz plane.

(Should be corrected, theta = 30.8°, phi = 0°).

Speculation about NCPM.

PAST WORK ON UNDOPED

(RE)AB

US Application 2006/0054864

YAB with less than 1000 ppm Mo

for generation of wavelengths < 350 nm.

SHG 532/266 nm observed,

no details provided.

COMPARISON

Present work: Based on Luo et al. (1989):

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)

Ph

ase m

atc

hin

g a

ng

le (

°)

Type I

Type II

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

W ave le ngth (µm )

Ph

ase m

atc

hin

g a

ng

le (

°)

Type I

Type II

SUMMARY OF NLO

PROPERTIES

1,9Approx.

6

0,410,6966,2YAB

1,96,20,490,861,5CLBO

4,850,171,147,5BBO

Walk-

off

(°)

T acc

(°C cm)

Ang acc

mradcm

deff

(pm/V)

Type I

Angle

SHG

532/266

nm

SUMMARY (cont‘d)

0,580,400,661,2851,641,0YAB

1,10,523,133,7BiBO

8-103,3

2,1

0,9

0,4

58,7

73,2

YCOB

63,83,150,80,6842,737LBO

13160,350,261,42,053931BBO

II

T acc

(°C cm)

I

T acc

(°C cm)

II

Ang acc

mradcm

I

Ang acc

mradcm

II

deff

(pm/V)

I

deff

(pm/V)

Type

II

angle

Type

I

angle

THG

355

nm

OUTLOOK AND FUTURE

WORK

• YAB, LuAB, YbAB, GdAB are promising

materials for UV generation.

• Phase matching conditions known and

verified for several wavelenths.

• Challenge: crystal growth of high purity

(low loss in UV range) material.

• Damage threshold ? Light induced effects?