Conference Papers

Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/28506

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Author: search.filters.author.Hegde, G.

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    Photoalignment of nematic liquid crystal by thin films of bishydrazones derived from 3,4 dipropyloxythiophene
    (2010) Alla, R.A.; Hegde, G.; Ravi, K.; Vasudeva Adhikari, A.V.; Vishnumurthy, K.A.; Komitov, L.
    Photoalignment of nematic liquid crystals (LC) promoted by thin films of bishydrazone derived from 3, 4 dipropyloxythiophene is studied. Experimental results show that bishydrazone without methyl group in their structure is promoting planar alignment parallel to the polarization direction of the actinic light whereas the ones with methyl group in the structure are promoting planar alignment perpendicular to light polarization direction. © 2010 ITE and SID.
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    Investigation of the photoalignment effect of 1, 3, 4-oxadiazoles bearing 2-fluoro-4-methoxy phenyl moiety
    (2010) Alla, R.A.; Hegde, G.; Isloor, A.M.; Chandrakantha, B.; Shetty, P.; Komitov, L.
    A new series of 1,3,4-oxadiazole derivatives containing 2-fluoro-4-methoxy moiety were synthesized by refluxing mixture of acid hydrazide 3 with different aromatic carboxylic acid in phosphorous oxychloride. Photoalignment studies were performed on these materials indicating that the position of fluorine plays vital role in promoting planar alignment either parallel or perpendicular to the light polarization direction. © 2010 ITE and SID.
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    Recent developments in photoalignment technology: Alignment properties of a thiophene based bis-hydrazone derivative
    (2012) Hegde, G.; Srivastava, A.K.; Vasudeva Adhikari, A.V.; Vishnumurthy, K.A.; Mohd Yusoff, M.M.; Chigrinov, V.G.; Kwok, H.S.
    Liquid crystal photoalignment on bis-hydrazones derived from thiophene derivatives is reviewed. Proposed material shows excellent alignment properties which is highly promisable for future applications. This photoalignment is based on reorientation phenomena attributed to thiophenes.
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    Urban land cover classification using hyperspectral data
    (International Society for Photogrammetry and Remote Sensing, 2014) Hegde, G.; Mohammed Ahamed, J.M.; Hebbar, R.; Raj, U.
    Urban land cover classification using remote sensing data is quite challenging due to spectrally and spatially complex urban features. The present study describes the potential use of hyperspectral data for urban land cover classification and its comparison with multispectral data. EO-1 Hyperion data of October 05, 2012 covering parts of Bengaluru city was analyzed for land cover classification. The hyperspectral data was initially corrected for atmospheric effects using MODTRAN based FLAASH module and Minimum Noise Fraction (MNF) transformation was applied to reduce data dimensionality. The threshold Eigen value of 1.76 in VNIR region and 1.68 in the SWIR region was used for selection of 145 stable bands. Advanced per pixel classifiers viz., Spectral Angle Mapper (SAM) and Support Vector Machine (SVM) were used for general urban land cover classification. Accuracy assessment of the classified data revealed that SVM was quite superior (82.4 per cent) for urban land cover classification as compared to SAM (67.1 per cent). Selecting training samples using end members significantly improved the classification accuracy by 20.1 per cent in SVM. The land cover classification using multispectral LISS-III data using SVM showed lower accuracy mainly due to limitation of spectral resolution. The study indicated the requirement of additional narrow bands for achieving reasonable classification accuracy of urban land cover. Future research is focused on generating hyperspectral library for different urban features.
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    Design, fabrication and characterization of 5 μm ring resonator
    (Optica Publishing Group (formerly OSA), 2016) Kollia, V.R.; Yadunath, T.R.; Resmi, R.K.; Hegde, G.; Badrinarayana, T.; Das, P.P.; Srinivas, T.
    We present the design, simulation, fabrication and characterization of microring resonator on SOI platform. Proposed feature size device resonates at a wavelength of 1565.92 nm. The fabricated device has potential applications in communication and sensing. © OSA 2016.
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    Multiple Order and Broadband Optical Orbital Angular Momentum Source using a Single Photonic Crystal Device
    (Institute of Electrical and Electronics Engineers Inc., 2020) Yadunath, T.R.; Ravindran, R.; Hegde, G.; Das, P.P.; Srinivas, S.
    A promising optical integrated circuit device design for the generation of broadband, low order OAM modes with topological charges of +1 and +2 is successfully conceptualized using a combination of ring and point defect in thin photonic crystal slab structure with circular array of holes. © 2020 IEEE.