|Search for content and authors|
Growth and characterization of YAl3(BO3)4 single crystal
|Simon Ilas 1, Alexandra Szemjonov 1, Pascal Loiseau 1, Gérard Aka 1, Takunori Taira 2|
1. Ecole Nationale Supérieure de chimie de Paris (ENSCP), 11 rue P. et M. Curie, Paris 75005, France
|Yttrium aluminum borate (YAB) is a potential candidate for UV applications especially at 266 nm. Many flux can be used to growth YAB: Li2O-B2O3, Li2O-B2O3-Al2O3, Li2WO4-B2O3. Here the flux La2O3-B2O3 is presented. Several undoped and Yb doped single crystals were grown. Physical parameters such as: thermal coefficients, absorption coefficent, refractive index and phase matching angles were determined. Moreover 14 % conversion efficiency from 532 to 266 nm were obtained using a YAB single crystal of 3 mm length.
The yttrium aluminum borate YAl3(BO3)4 (YAB) is a very promising nonlinear material for UV applications. YAB crystallizes in the space group R32. Its structure is built from [BO3]3- anionic groups. This material is currently widely studied because of its great potential for UV generation. In fact, it has a lot of good properties such as large NLO coefficient, moderate birefringence and good physical and chemical stability. The intrinsic UV cut-off wavelength was reported to be 160 nm. Nevertheless, one of the drawbacks is the hindered transparency of YAB crystals below 300 nm. Fe3+ ions can enter in the structure in substitution of Al3+ and cause some very efficient charge-transfer transitions between 300 and 200 nm. Moreover, the crystal growth is not well mastered yet. Because of its non-congruent melting, YAB crystals have to be grown using a flux. Many flux can be used: Li2O-B2O3 , Al2O3-Li2O-B2O3 , Li2WO4-B2O3 .We present here the study of the flux La2O-B2O3. Several undoped and Yb doped crystals with weight of 15-20 g were obtained by cooling under air the melt in the temperature range: 1150 °C - 1100 °C. The average thermal expansion coefficients were determined: α1 = 4,3.10-6 K-1 and α3 = 1,23.10-6 K-1. The absorption coefficient at λ = 266 nm is α ≅ 2,9 cm-1. Measurement of refractive index and phase matching angle were determined. The environement of Yb3+ is studied by EPR and FTIR spectroscopy to evaluate the crystal quality. Moreover, crystals were cut in ZX plane for Type I SHG (532 --> 266 nm) (Fig. 1). 14 % conversion efficiency was obtained using a YAB single crystal of 3 mm length. The infrared source emits 1,6 mJ/pulse with a pulse duration of 500 ps at a frequency of 100 Hz. A 10 mm long type-I LiB3O5 (LBO) was used to obtain green power.
Fig. 1: YAB single crystal cut in the ZX plane for 266 nm generationX. Yu et al, Journal of Crystal Growth, 312, 3029–3033 (2010)
J. Yu et al, Journal of Crystal Growth, 341, 61-65 (2012)
H. Liu et al, Materials Research Innovations, 15, 102-106 (2011)
Presentation: Oral at 17th International Conference on Crystal Growth and Epitaxy - ICCGE-17, Topical Session 6, by Simon Ilas
See On-line Journal of 17th International Conference on Crystal Growth and Epitaxy - ICCGE-17
Submitted: 2013-04-12 14:40 Revised: 2013-07-23 18:23