Characterization of LiInS 2 and LiInSe 2 single crystals for nonlinear optical applications
- PDF / 102,290 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 6 Downloads / 213 Views
Characterization of LiInS2 and LiInSe2 single crystals for nonlinear optical applications Ludmila Isaenko, Alexander Yelisseyev, Sergei Lobanov, Alexander Panich,1 Vitaly Vedenyapin, Julia Smirnova, Valentin Petrov,2 Jean-Jacques Zondy,3 and Guido Knippels4 Design & Technological Institute for Monocrystals SB RAS, Novosibirsk 630058 Russia 1 Ben-Gurion University of the Negev, Dept of Physics, P.O.Box 653, 84105 Beer Sheva, Israel 2 MB-Institute for Nonlinear Optics and Ultrafast Spectroscopy, D-12489, Berlin, Germany 3 Laboratoire Observatoire de Paris, 61 Avenue de l’Observatoire, F 75014, Paris, France 4 FOM-Institute for Plasma Physics, Edisonbaan 14, 3439 MN, Nieuwegeln, the Netherlands ABSTRACT X-ray structural analysis, nuclear magnetic resonance, optical spectroscopy and second harmonic generation were used to characterize the new nonlinear crystals LiInS2 and LiInSe2 which possess maximum band gap (3.59 and 2.86 eV at 300 K, respectively) among ternary chalcogenides. As grown crystals are only slightly colored while color change after annealing is due to native point defects. INTRODUCTION Only few suitable nonlinear crystals are available for generation of coherent radiation tunable in the mid-IR (3 to 20 µm), a spectral region of great importance for vibrational molecular spectroscopy and atmospheric sensing. An active search for new nonlinear crystals for this region is in progress now. The new materials that can be successfully added to this limited list of crystals are LiInS2 and LiInSe2 (further LIS, LISe, respectively). The first one was first studied by Boyd and co-workers in the 70-ies [1], and has recently enjoyed renewed interest because of its attractive optical properties, such as the large transparency range from 0.35 to 13 µm and the high (estimated at 10.6 µm [1]) nonlinear susceptibility d33=15.8 pm/V. No information about the nonlinearity of LISe was available, but it was expected to be higher. Problems with growth of the LiInS2 and LiInSe2 crystals were solved recently and large crystals of high optical quality became available [2,3]. One of the typical features of ternary compounds is considerable variation of their color depending on growth or annealing conditions. Taking into account that such coloration can be due to phase transitions and affect strongly the main output parameters including nonlinear efficiency, we studied LIS and LISe samples of different color using several structurally sensitive techniques: X-ray structural analysis, nuclear magnetic resonance (NMR), frequency conversion (nonlinear susceptibility and phase-matching conditions) and optical spectroscopy and showed that color variations can be due to point defects. EXPERIMENTAL DETAILS AND DISCUSSION Samples: Crystal growth and annealing The bulk LIS and LISe crystals were grown by the Bridgman-Stockbarger technique on (001) and (010) seeds. Details of LIS growth were given in [2], the growth techniques for LISe is very similar. Special attention is paid to ratios between components in the charge. A correction of the s
Data Loading...
