Fabrication and performance study of electro-optical modulator and third order nonlinearity using unidirectional method (Sankaranarayanan–Ramasamy) grown Imidazolium l-Tartrate 〈0 1 0〉 single crystal

Abstract

The results of electro-optical modulator and third order nonlinearity of an organic single crystal of Imidazolium l-tartrate (IMLT) 〈010〉 grown by unidirectional growth method of Sankaranarayanan–Ramasamy (SR) are discussed for the first time in literature. The grown IMLT seed crystals were characterized by single crystal XRD and the lattice parameters were confirmed. The UV–Visible transmittance analysis shows that SR method grown IMLT single crystal possesses good transmittance in the entire visible region with a low cut-off wavelength at 240nm. The mechanical study on the (010) plane of the IMLT single crystal analyzed by Vickers microhardness tester reveals the moderate hardness of the material. Photoconductivity studies on pure IMLT single crystal enumerated the positive photoconducting nature. Refractive index of the IMLT single crystal was determined by Brewster angle method. Second Harmonic Generation (SHG) efficiency of IMLT is 4.3 times greater than the standard Potassium Dihydrogen Phosphate (KDP) crystal. Nonlinear refractive index (n2), nonlinear absorption coefficient (β) and third-order nonlinear optical susceptibility χ(3) were evaluated using Z-scan method. The half wave voltage and electro-optical coefficient of IMLT crystal were determined using polarimetric technique. The electro-optical coefficient (r12) of IMLT is found to be greater than that of KDP crystal which represents the suitability of IMLT crystal to design the electro-optical modulator with low half wave voltage for nonlinear optical applications.