Ravindra H J
@sode-edu.in
Professor, Physics
Shri Madhwa Vadiraja Institute of Technology and Management
EDUCATION
MSc, PhD
RESEARCH, TEACHING, or OTHER INTERESTS
Condensed Matter Physics, Atomic and Molecular Physics, and Optics
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
H. Ramakantha Puranik, Ravindra H.J., and B. Praveen Managutti
Elsevier BV
Usha Harish and Ravindra Hadya Jayaramu
AIP Publishing
Ramakantha Puranik H., Hadya Jayaramu Ravindra, Praveen B. Managutti, Shubha, Tayur N. Guru Row, and Harish Usha
AIP Publishing
A chalcone derivative (2E)-3-(5-bromothiophen-2-yl)-1-(naphthalen-1-yl) prop-2-en-1-one (NBT) has been synthesized by Claisen-Schmidt condensation reaction and grown into single crystal by slow evaporation solution method. Elemental analysis, 1H NMR spectra and FTIR spectral studies confirm the structure of the molecule. The melting point of NBT is 112 °C and single crystal X-ray diffraction analysis reveals that NBT crystalizes in triclinic crystal system with centrosymmetric space group P -1. The material is transparent in the visible region with a cutoff wavelength 454 nm and its direct transition energy gap was found to be 3.1 eV. Theoretical calculations using density functional theory (DFT) reveal that the first hyperpolarizability (β) of NBT in the gaseous state is 20.8 x10−30 esu and the HOMO-LUMO energy difference is 3.57 eV. The theoretical second hyperpolarizability (γ) of NBT was found to be 5.32x10-35 esu.
Sandhya, H. J. Ravindra, Praveen B. Managutti, and Tayur N. Guru Row
AIP Publishing
Vijaya Kumari, Hadhya Jayaramu Ravindra, and Harish Usha
AIP Publishing
Vijaya Kumari, H. J. Ravindra, and H. Usha
AIP Publishing
H. Ramakantha Puranik and H. J. Ravindra
AIP Publishing
A chalcone derivative (2E)-3-(4-bromophenyl)-1-(4-methoxyphenyl)prop-2-en-1-one (BMC) has been synthesized and grown into single crystal. Elemental analysis, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectral analysis and powder X-ray diffraction studies were carried out to confirm the structure of the molecule. The TG/DT analysis shows that the crystal has good thermal stability with a melting point of 159 °C. The UV-Visible absorption study shows that the crystal has good transparency in the visible region with a cutoff wavelength 422 nm and direct transition energy gap of 3.5 eV. The second harmonic generation (SHG) efficiency of BMC was found to be 2.22 U and possess phase matching property. Theoretical calculation of molecular first hyperpolarizability (β) of BMC in gaseous state was computed using density functional theory (DFT) and was found to be 16.5 × 10−30 esu. High thermal stability, good transparency in visible region, good SHG efficiency and phase matching property of BMC makes it a possible potential candidate for NLO device applications.A chalcone derivative (2E)-3-(4-bromophenyl)-1-(4-methoxyphenyl)prop-2-en-1-one (BMC) has been synthesized and grown into single crystal. Elemental analysis, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectral analysis and powder X-ray diffraction studies were carried out to confirm the structure of the molecule. The TG/DT analysis shows that the crystal has good thermal stability with a melting point of 159 °C. The UV-Visible absorption study shows that the crystal has good transparency in the visible region with a cutoff wavelength 422 nm and direct transition energy gap of 3.5 eV. The second harmonic generation (SHG) efficiency of BMC was found to be 2.22 U and possess phase matching property. Theoretical calculation of molecular first hyperpolarizability (β) of BMC in gaseous state was computed using density functional theory (DFT) and was found to be 16.5 × 10−30 esu. High thermal stability, good transparency in visible region, good SHG efficiency and phase matching property ...
H. Usha and H. J. Ravindra
AIP Publishing
In the present paper the chalcone belonging to D-π-A type push-pull system has been synthesized and the single crystals were grown by controlled solution evaporation technique. The grown single crystals were subjected to NMR, FTIR and powder X-ray diffraction technique to confirm the compound. The linear optical cut-off was found to be at 442 nm. The SHG efficiency was determined in powder form and was found to be 1.57 times that of KDP. The titled chalcone was found to be stable up to 106 °C. The DFT calculations revealed that the intermolecular interaction assisted molecular alignment play a crucial role in SHG. The un-optimal alignment of the molecules in the crystal structure resulted in decreased intermolecular charge transfer in the crystal. The structure-property relation is presented based on the experimental and DFT calculations.
Sandhya, H. J. Ravindra, P. B. Managutti, and T. N. G. Row
AIP Publishing
Heng Lu, Bing Gu, Yiping Cui, Jun He, Kumari Vijaya, H. J. Ravindra, and H. Usha
World Scientific Pub Co Pte Lt
We report the theoretical and experimental investigations of structure–property relationships for [Formula: see text] at the wavelength of 800[Formula: see text]nm in three D-[Formula: see text]-A-[Formula: see text]-A type chalcone derivatives. Theoretically, the second hyperpolarizability [Formula: see text] at the wavelength of 800[Formula: see text]nm is numerically computed from the combination of density functional theory and semi-empirical method. Experimentally, we synthesize these three chalcone derivatives and investigate their nonlinear optical (NLO) properties using the femtosecond-pulsed [Formula: see text]-scan measurements at 800[Formula: see text]nm. It is shown that the dependence of the measured [Formula: see text] on the molecular structure has a trend, consistent with that of computational [Formula: see text]. These results indicate that the enhancement of the NLO response can be realized by design of the electron donating strength in the D-[Formula: see text]-A-[Formula: see text]-A type molecule.
Anthoni Praveen Menezes, A. Jayarama, and H.J. Ravindra
Elsevier BV
Anthoni Praveen Menezes, A. Jayarama, and H.J. Ravindra
Elsevier BV
A. Jayarama, H.J. Ravindra, Anthoni Praveen Menezes, S.M. Dharmaprakash, and Seik Weng Ng
Elsevier BV
D. Sajan, H.J. Ravindra, Neeraj Misra, and I. Hubert Joe
Elsevier BV
A. John Kiran, H.W. Lee, H.J. Ravindra, S.M. Dharmaprakash, K. Kim, H. Lim, and F. Rotermund
Elsevier BV
A. John Kiran, H. W. Lee, H. J. Ravindra, S. M. Dharmaprakash, K. Kim, H. Lim, and F. Rotermund
IEEE
A new chalcone crystal designed with suitable functional groups exhibits ultrafast response (<90 fs) and very large two-photon absorption (2PA) (β > 8 ×10<sup>2</sup> cm/GW). Its low intensity threshold (<4 MW/cm<sup>2</sup>) for 2PA and high damage resistance (>8 GW/cm<sup>2</sup>) are quite interesting for 2PA-based optical limiting.
H. J. Ravindra, K. Chandrashekaran, W. T. A. Harrison, and S. M. Dharmaprakash
Springer Science and Business Media LLC
A. Jayarama, H.J. Ravindra, and S.M. Dharmaprakash
Elsevier BV
H.J. Ravindra, W.T.A. Harrison, M.R. Suresh Kumar, and S.M. Dharmaprakash
Elsevier BV
H.J. Ravindra, A. John Kiran, S.M. Dharmaprakash, N. Satheesh Rai, K. Chandrasekharan, B. Kalluraya, and F. Rotermund
Elsevier BV
H.J. Ravindra, A. John Kiran, Satheesha Rai Nooji, S.M. Dharmaprakash, K. Chandrasekharan, Balakrishna Kalluraya, and Fabian Rotermund
Elsevier BV
A. John Kiran, H. C. Kim, K. Kim, F. Rotermund, H. J. Ravindra, S. M. Dharmaprakash, and H. Lim
AIP Publishing
High-quality biaxial single crystals of chalcone derivatives were grown by solution growth technique. Their molecular structures were designed to possess large second-order nonlinearities by choosing proper donor/acceptor groups while retaining a high transparency in the visible and infrared spectral regions. The second-order nonlinear optical coefficients, determined by applying the Maker fringe technique, were found to be much larger than those of LiB3O5, KTiOPO4, KH2PO4, and urea. The advantages, such as easy synthesis and crystal growth, low cutoff wavelength (&lt;450nm), large optical nonlinearity, and high damage threshold (&gt;7.2GW∕cm2), make these organic crystals promising for efficient frequency doubling.
William T. A. Harrison, H. J. Ravindra, M. R. Suresh Kumar, and S. M. Dharmaprakash
International Union of Crystallography (IUCr)
In the title compound, C22H17NO, the dihedral angles between the central benzene ring and the two terminal phenyl rings are 48.20 (4) and 49.62 (4)°, resulting in a substantially twisted molecular conformation. Weak C—H⋯π interactions help to consolidate the centrosymmetric crystal packing.
William T. A. Harrison, H. J. Ravindra, M. R. Suresh Kumar, and S. M. Dharmaprakash
International Union of Crystallography (IUCr)
In the title cocrystal, 0.972(C18H19NO4).0.028(C17H16BrNO3), which arose from an impure starting material, all the atoms are overlapped except for one OMe group and the Br atom. The dihedral angle between the benzene ring mean planes is 18.20 (13)°. A weak N—H⋯O hydrogen bond helps to establish the non-centrosymmetric crystal packing.