Subhasis Das

University of Burdwan, Burdwān, West Bengal, India

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Publications (5)14.72 Total impact

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    ABSTRACT: Recent trends focuses on the usage of nonlinear optical materials owing to its increasing demand in frontier areas of optical communication and switching applications. In the present work single crystal of L-Threoninium picrate, an excellent material for nonlinear optical applications was grown using conventional slow evaporation solution technique to meet the increasing demand of photonics industry. The lattice parameters of the grown crystal were analysed by using powder X-ray diffraction and found that it crystallised in monoclinic system with space group P21.The strain in the lattice of grown crystal was calculated using Hall-Williamson relation. Crystalline perfection of the grown crystal was assessed using High Resolution X-ray diffraction technique and observed that quality of crystal is fairly good. Optical transmission analysis and bandgap evaluation was performed using UV-Vis spectroscopy. Laser damage threshold value for the crystal was also measured and found that it is higher than most of reported organic single crystals. Optical homogeneity of the crystal and birefringence was evaluated using modified channel spectrum method. Thermal behaviour of the grown specimen was examined by using photopyroelectric technique. Further its various mechanical properties like hardness, stiffness, young’s modulus etc were measured using nano-indentation technique. Keywords: High Resolution X-ray diffraction, nano-indentation, birefringence, slow evaporation, photopyroelectric
    RSC Advances 10/2014; 4:56188. DOI:10.1039/C4RA09410G · 3.84 Impact Factor
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    ABSTRACT: An organic nonlinear optical single crystal of ninhydrin was grown by Sankaranarayanan–Ramasamy (SR) method by using specially designed glass ampoule. The good quality seed crystal has been prepared by conventional solution growth technique using double distilled water as the solvent. The lattice dimension of the grown specimen was identified from the powder X-ray diffraction analysis and found that it crystallized in a monoclinic system with non-centrosymmetric space group P21. The presence of functional groups was examined by Fourier transform infrared (FTIR) analysis and it was found that there was no incorporation of foreign elements during crystallization. The surface defects were assessed by optical microscope and the dielectric constant and dielectric loss were carried out by LCR meter. Laser damaged threshold, relative second harmonic generation (SHG) and phase matching were measured by using a high intensity Nd:YAG laser as a source having the wavelength of 1064 nm. Its thermal stability has been assessed by TG–DTA and specific heat measurements with respect to different temperatures. The optical studies show that the crystal has transmittance ability of light in the entire visible region.
    CrystEngComm 01/2013; 15(11). DOI:10.1039/C2CE26710A · 4.03 Impact Factor
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    ABSTRACT: a b s t r a c t Optical quality c-glycine single crystal of dimension 9 Â 9 Â 8 mm 3 has been grown by slow cooling method in the presence of lithium nitrate. The third order nonlinear refractive index and nonlinear absorption coefficient of the grown crystal were measured by Z-scan studies. The dispersion of birefrin-gence behaviour was studied by modified channelled spectrum method. The relative second harmonic generation efficiency of grown crystal was measured by Kurtz and Perry technique and phase matching angle was also measured using Nd:YAG laser. Ó 2012 Elsevier B.V. All rights reserved.
    Optical Materials 12/2012; 35(2-2):307-309. DOI:10.1016/j.optmat.2012.09.009 · 1.98 Impact Factor
  • N. Vijayan · G. Bhagavannarayana · S. N. Sharma · Subhasis Das ·
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    ABSTRACT: In the present communication, we have successfully synthesized the efficient NLO material of glycine hydrofluoride (GHF) by conventional chemical reaction, and grown the single crystal by adopting slow evaporation solution growth technique. In order to know its suitability for device fabrication, different characterization analyses have been performed. The lattice constants have been determined from powder X-ray diffraction (PXRD) method and found that it crystallizes in orthorhombic crystal system. Its crystalline perfection was evaluated by high-resolution X-ray diffraction technique (HRXRD) and the value of FWHM indicates the presence of low angle structural grain boundaries. Its luminescence behaviour has been analysed by photoluminescence (PL) analysis and found maximum luminescence in the lower wavelength region. Its relative second harmonic generation efficiency was evaluated from Kurtz powder technique. The phase matching angle of GHF was determined by using Nd:YAG laser as a source. Its thermal, mechanical and electrical properties were examined by TG/DTA, Vickers microhardness tester and dielectric measurements, respectively.
    Journal of Materials Science 07/2009; 44(13):3457-3461. DOI:10.1007/s10853-009-3459-y · 2.37 Impact Factor
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    ABSTRACT: Good quality single crystals of benzimidazole (BMZ) (4 × 5 × 6 mm3) have been successfully grown by solvent evaporation method using methanol as the solvent. The grown crystal belongs to orthorhombic system and the lattice constants were found from the powder X-ray diffraction analysis. The refractive index was determined at two different wavelengths by Brewster's angle method and found to be 1.607 and 1.613 respectively. The dielectric constant and dielectric loss of the crystal was studied as a function of frequency with different temperatures and the results are discussed. The optical band gap has been determined from the UV–Vis., analysis, and found that 4.1 eV. Such a wide band gap materials are useful for photonic and optoelectronic applications. The luminescence behavior has been examined in the wavelength region between 500–800 nm by using Ar+ ion laser as a source. The relative second harmonic generation (SHG) efficiency of the grown specimen is 4.5 times greater than that of the potassium dihydrogen phosphate (KDP) single crystal. Its phase matching angle has also been determined.
    Materials Letters 03/2008; 62(s 8–9):1252–1254. DOI:10.1016/j.matlet.2007.08.023 · 2.49 Impact Factor