Vers la croissance des cristaux de KTiOPO 4 périodiquement alternés de grande taille

Transcription

1 Vers la croissance des cristaux de KTiOPO 4 périodiquement alternés de grande taille Alexandra Peña Revellez 1, Bertrand Ménaert 1, Benoît Boulanger 1, Carlota Canalias 2, Valdas Pasiskevicius 2, Fredrick Laurell 2, Patricia Segonds 1, Jérôme Debray 1, Corinne Félix 1, Sébastien Pairis 1, Olivier Fruchart 1, Luc Ortega 1 (1) Institut Néel CNRS/UJF, Grenoble, France (2) Royal Institut of Technology, Stockholm, Sweden Journées CRISTECH 2010, Autrans 4-6 octobre

2 Outline PERIODICALLY POLED CRYSTALS Non linear frequency conversion: Quasi Phase Matching interest Need of large size crystals THE STATE OF THE ART Obtention by electric field poling Crystal growth by CZ and TSSG GROWTH METHOD PROPOSED IN THE PRESENT WORK General Scheme Definition of the crystal growth conditions First results FURTHER AIMS

3 Outline PERIODICALLY POLED CRYSTALS Non linear frequency conversion: Quasi Phase Matching interest Need of large size crystals THE STATE OF THE ART Obtention by electric field poling Crystal growth by CZ and TSSG GROWTH METHOD PROPOSED IN THE PRESENT WORK General Scheme Definition of the crystal growth conditions First results FURTHER AIMS

4 Non linear frequency conversion: Quasi Phase Matching Interest SINGLE DOMAIN CRYSTAL P s KTiOPO 4 Birefringence Phase Matching (d 24 ) 2 4 pm 2 /V 2 PERIODICALLY POLED CRYSTAL 10 P s e 1 mm Quasi Phase Matching ( x d 33 ) 2 40 pm 2 /V 2

5 Need of large size crystals OPTICAL PAREMETRIC DEVICES OF HIGH POWER = I max = optical damage threshold PARAMETRIC INTERACTIONS BY ANGULAR QUASI PHASE MATCHING L i = Petit, Boulanger, Segonds, Taira, Physical Review A (2007) Brand, Boulanger, Segonds, Petit, Félix, Ménaert, Taira, Optics Letters (2009)

6 Outline PERIODICALLY POLED CRYSTALS Non linear frequency conversion: Quasi Phase Matching interest Need of large size crystals THE STATE OF THE ART Obtention by electric field poling Crystal growth by CZ and TSSG GROWTH METHOD PROPOSED IN THE PRESENT WORK General Scheme Definition of the crystal growth conditions First results FURTHER AIMS

7 The state of the art Two different processes using a single domain crystal ELECTRIC FIELD POLING Metallic electrodes Λ CRYSTAL GROWTH Growth from single domain seeds by modulating the growth conditions High electric field PPKTP Λ e (001) Λ Grating period a c b Advantage: control of the grating period Λ Limitation: small thickness (e) e 1 mm for PPKTP if Λ = µm Fejer, Magel, Jundt, Byer, IEEE Journal of Quantums Electronics (1992) Advantage: large dimension crystals Limitation: bad control of Λ Bermudez, Callejo, Dieguez, Journal of Crystal Growth (1999) Roth, Angert, Tseitlin, Journal of Materials Science : Materials in Electronics (2001)

8 Outline PERIODICALLY POLED CRYSTALS Non linear frequency conversion: Quasi Phase Matching interest Need of large size crystals THE STATE OF THE ART Obtention by electric field poling Crystal growth by CZ and TSSG GROWTH METHOD PROPOSED IN THE PRESENT WORK General Scheme Definition of the crystal growth conditions First results FURTHER AIMS

9 P s Growth method proposed in the present work Single domain KTP slab A combination of the two classical processes c STEP I INVERSION BY ELECTRIC FIELD PPKTP SEED (001) a b (001) Λ Grating period KTH, Stockholm C. Canalias, V. Pasiskevicius, F. Laurell Electrodes 10 6 V/cm High electric field PPKTP SEED Λ Grating period (001) STEP II EPITAXIAL GROWTH (001) Seed Growth zone Institut Néel, Grenoble A. Peña, B. Ménaert, B. Boulanger High temperature solution Pt crucible Furnace a - Growth onto {001} - Domains propagation c b

10 Definition of the crystal growth conditions Temperature REQUIREMENTS: T Croissance < (T Curie, T Roughening {001} ) Paraelectric phase mmm (P s = 0) K 6 P 4 O 13 flux KPO 3 - KF flux Advantage: T Curie T Roughening {001} Ferroelectric phase mm2 (P s 0) P s (201) (200) (001) (201) - (011) (110) - (011) (110) - Advantage: High growth rate Limitation: Domain of temperature of KTP phase : K 7 TiP 5 O 18 under 820 C Domain of temperature of KTP phase : KTP phase until solidification Possibility to work under T Roughening {001} Crystal growth working zone P s (200) (201) (201) (011) (110) (110) - - (011) - Impossible to work under T Roughening {001} c faces cannot exist! c faces can exist! (001) T Eutectic Solid phase Limitation: Lower growth rate

11 First results PPKTP epitaxial growth from PPKTP seed CHEMICAL SYSTEM KTP - KPO3 - KF c Grown layer Initial seed Grown layer Submerged seed a a b a b c b a b Epitaxy of PPKTP c c Scanning Electron Microscopy (SEM) image Piezo reponse Force Microscopy (PFM) image Propagation of the domains over the full width (1 mm by now) of the grown layer!!! But: Low growth rate 2 µm/h

12 Outline PERIODICALLY POLED CRYSTALS Non linear frequency conversion: Quasi Phase Matching interest Need of large size crystals THE STATE OF THE ART Obtention by electric field poling Crystal growth by CZ and TSSG GROWTH METHOD PROPOSED IN THE PRESENT WORK General Scheme Definition of the crystal growth conditions First results FURTHER AIMS

13 Further aims Decreasing the viscosity INCREASE THE GROWTH RATE Pull of the crystal ω 1000 C 600 C Working line [KF] Two possible ways:. Increase [KF] η D. Other flux: 3K 2 WO 4 P 2 O 5 [1] [1] Ballman, Brown, Olson, Journal of Crystal Growth (1986) Pulling along [001]. Directed matter transfer. Extraction of latent crystallization heat

14 Summary IN SITU METHOD TO GROW PERIODICALLY POLED CRYSTALS For PPKTP crystals: - Definition of the growth conditions - First demonstration of growth of PPKTP thick layers with a perfect grating period (Λ)

15 Merci pour votre attention Acknowledgements: To the program BP-DGR 2008 of the Agency for Administration of University and Research Grants (AGAUR) for the financial support.

16 z z n y n x x φ θ θ Λ Λ y Λ eff n y n z cristal biaxial positive x

17 Increase of [KF] Diminution of the viscosity η [1] ln η Increase of the growth rate f [2] Increase of the diffision D f α η -1/6 η /10 f 1,5 D = k B T/6πηr [1] Shaw, American Journal of Science (1972) [2] Van Erk, Jounal of Crystal Growth (1978)