Optical absorption of tris thiourea zinc sulphate (ZTS) single crystals has been measured and its direct band gap was found to be 3.6 eV. Theoretical calculations were carried out to determine the linear optical constants such as extinction coefficient and refractive index. Further the optical nonlinearties of ZTS have been investigated by Z-scan technique with He-Ne laser at 632.8 nm. The nonlinear refractive index, absorption coefficient and third order susceptibility is found to be in the order of –5.36 ± 0.26 × 10–12 cm2/W, 4.24 ± 0.21 × 10–4 cm/W, 3.5 ± 0.17 × 10–4 esu respectively. Thus optical characterization of ZTS reveals the various industrial application oriented properties of the material. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Linear and nonlinear optical properties of tris thiourea zinc sulphate single crystals

Solution Growth of a Novel Nonlinear Optical Material: L-Histidine Tetrafluoroborate

Synthesis, crystal growth and studies on non-linear optical property of new chalcones

Over the past two years, the field of molecular nonlinear optics has benefited from both upstream rejuvenation (the emergence of new molecular engineering guidelines) and downstream application-oriented breakthroughs, helping to bring the field closer to industrial developments. In the fundamentals areas, traditional perspectives based on the paranitroaniline ‘molecular diode’ template are being enlarged to encompass three-dimensional multicharge transfer ‘multipolar’ systems with dipolarless ‘octupoles’, demanding that earlier models and experiments be thoroughly revisited. Furthermore, the relevance of polar structures primarily targeted towards quadratic nonlimear optics has been extended to cubic all-optical processes based on a cascaded sequence of quadratic processes. In the application domain, progress in crystal growth is best illustrated by the demonstration of low threshold pulsed near-IR optical parametric oscillators based on stable organic or organomineral crystals. Functionalized polymers have confirmed their current supremacy as organic optoelectronic device materials with the reports of low voltage electro-optic modulation in integrated waveguide structures and high modulation bandwidth.

Status and perspective for molecular nonlinear optics: from crystals to polymers and fundamentals to applications

Growth and characterization of an organic NLO crystal: 1-(4-methylphenyl)-3-(4-methoxyphenyl)-2-propen-1-one

The crystal structure, refractive indices, and phase-matching conditions for a new nonlinear optical material, L-histidine tetrafluoroborate (HFB), are reported. HFB grows readily, displays favorable mechanical characteristics, and has adequate birefringence to permit phase-matched parametric processes over much of its transparency range (250 nm to 1300 nm). The phase-matching loci and angular sensitivity for second-harmonic generation of 1064-nm light in single crystals of HFB were measured. The effective nonlinearity for HFB is comparable with that of beta-barium borate (~2 pm/V), and its angular sensitivity [delta(Deltak)/deltatheta] is somewhat smaller.

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L. A. DeLoach

Papers

L-Histidine tetrafluoroborate: a solution-grown semiorganic crystal for nonlinear frequency conversion.