Bulk Crystal growth and Characterization of Organic Nonlinear Optical Crystal: 2-(2,4-dimethoxybenzylidene) malononitrile (DMM)

Abstract

Bulk organic nonlinear optical single crystal of 2-(2,4-dimethoxybenzylidene) malononitrile (DMM) with size up to 24×18×13 mm 2 was successfully grown by slow evaporation solution growth technique. The single crystal X-ray diffraction studies of the grown crystal exhibit that the crystal belongs to a monoclinic system with P21/n space group. The FT-IR spectrum confirms the various functional groups present in the grown crystal. The optical properties of the grown crystals were analyzed by UV–Vis-NIR spectral analysis. Third-order nonlinear optical behaviour of the title crystal was studied by Z-scan technique. All the finding results in the present work indicate that DMM has a potential application as a useful NLO candidate. Introduction. In recent years, organic non-linear optical (NLO) crystals have gained considerable attention due to their relatively high nonlinearity and fast response. Particularly, third order nonlinear optical (TONLO) organic materials have gained much consideration because of their promising applications in optical switching, optical data processing, optical limiting, signal processing and ultra-fast optical communications, etc [1,2]. The centrosymmetric organic crystals with good stability lead to third order susceptibility (χ (3)) and higher nonlinear absorption coefficient (β) and fast response time for nonlinear optical properties. However, only very few organic materials could so far be crystallized in reasonable crystal size and optical grade to realize various applications. For the first time, we present here investigations on the bulk growth of DMM organic crystals and its different characterizations.