Sn2P2S6 Crystals for Fast Near-Infrared Photorefraction

• Published in: Ferroelectrics 2005-01, Vol.318 (1), p.89-94
• Main Authors: Jazbinsek, M., Haertle, D., Bach, T., Montemezzani, G., Güunter, P., Grabar, A. A., Vysochanskii, Yu. M.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectric, piezoelectric, ferroelectric and antiferroelectric materials; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Elements, oxides, nitrides, borides, carbides, chalcogenides, etc; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Nonlinear optics; Optics; phase conjugation; Phase conjugation, optical mixing; photorefractive and kerr effects; photorefractive effect; Physics; two-beam coupling
• ISSN: 0015-0193; 1563-5112
• DOI: 10.1080/00150190590966108

Optical and physical properties of Sn 2 P 2 S 6 ferroelectric crystals suitable for photorefractive applications in the red and near-infrared spectral range are reported. The main advantage of Sn 2 P 2 S 6 is its high beam-coupling gain combined with considerably faster response in the near infrared compared to conventional oxide-type photorefractive materials. We show that modifying the growth conditions and doping with Te can efficiently improve the photorefractive properties of Sn 2 P 2 S 6 . Photorefractive two-beam coupling gain at 860 nm increases from about 2 cm − 1 in conventional "yellow" Sn 2 P 2 S 6 to about 7 cm − 1 in Te-doped samples and 14 cm −1 in modified "brown" samples. We examine the self-pumped optical phase conjugation properties of Sn 2 P 2 S 6 in a ring-cavity scheme. Phase-conjugate signals with amplitudes close to the theoretical limit and rise times of about 10 ms for 4 W/cm 2 pump intensity at 780 nm and 50 ms for 2.5 W/cm 2 pump intensity at 860 nm are obtained. *Present Address: Laboratoire Matériaux Optiques, Photonique et Systèmes (LMOPS), University of Metz and Supélec, F-57070 Metz, France.