| Personal Information |
| NAME |
HARSH PURWAR |
| DATE OF BIRTH |
16 March 1988 |
| GENDER |
Male |
| FATHER'S NAME |
Mr. Vinod Kumar Purwar |
| PRESENT ADDRESS |
Indian Institute of Science Education and Research, Kolkata |
| |
Mohanpur Campus, PO: BCKV Main Campus Office |
| |
Mohanpur, Nadia - 741 252 |
| |
West Bengal, India |
| MOBILE NO. |
+91 9903361473 |
| EMAIL |
harshpurwar@hotmail.com, harsh@iiserkol.ac.in |
| PERMANENT ADDRESS |
S/o Mr. Vinod Kumar Purwar |
| |
House No. G - 729, Awas Vikas No. 1 |
| |
Kailash Vihar, Kalyanpur |
| |
Kanpur - 208 017 (U.P), India |
| TEL. NO. |
+91 512 2574797 |
| LANGUAGES |
English, Hindi |
| NATIONALITY |
INDIAN |
|
|
| Research Interests |
| My interests, broadly, lie in the field of optics/nano-optics. During my five years integrated dual B.S. - M.S. course at IISER - Kolkata, India, I believe, I have developed appreciable experimental and theoretical skills in various fields of physical sciences with an exceptionally good computational expertise. With these strengths, I wish to pursue an exciting and challenging career in science. I have pursued every opportunity to participate in various research projects in these fields within and outside my campus. I want to explore these exciting interdisciplinary fields even further, because I believe it is a field unique in its ability to encompass and demand contribution from several aspects of science. I have been successful in maintaining a healthy score at the academic front. I am self-motivated, committed and determined in achieving my goals. I also possess appreciable verbal and written communication skills. |
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|
| Educational Qualifications |
| 2007 - 2012 |
Five years Integrated Dual B.S. - M.S. |
| DISCIPLINE |
Physical Sciences |
| INSTITUTION |
Indian Institute of Science Education and Research, Kolkata, India |
| CGPA |
8.29 (absolute grading & in scale of 10.) |
| SEMESTER GPA |
Sem 1: 8.44 Sem 3: 8.13 Sem 5: 7.71 Sem 7: 7.17 Sem 9: 9.00 |
| |
Sem 2: 8.67 Sem 4: 7.88 Sem 6: 8.14 Sem 8: 8.00 Sem 10: 10.00 |
| MAJOR COURSES |
Classical Mechanics, Quantum Mechanics, Electrodynamics, Condensed Matter Physics, Statistical Mechanics, General Relativity & Cosmology, Thermodynamics, Electronics, Computational Physics, Waves & Optics, Nuclear & Particle Physics, Theoretical High Energy Physics, Quantum Field Theory, Advanced Mathematical Methods and Atomic & Molecular Physics. |
| OTHER COURSES |
Real Analysis, Linear Algebra, Complex Analysis, Probability & Statistics, Chemistry of Elements, Cell Biology, Chemical Dynamics & Energetics, Genetics, Spectroscopy, Evolutionary Biology & Ecology, Bonding Structure & Symmetry, Biological Systems. |
| 2005 - 2006 |
All India Senior Secondary Certificate Examination (Class XII) |
| BOARD |
Central Board of Secondary Education |
| SCHOOL |
Delhi Public School, Kalyanpur, Kanpur, Uttar Pradesh, India |
| SUBJECTS |
Mathematics, Physics, Chemistry, Computer Science and English. |
| MARKS OBTAINED |
78.4% |
| 2003 - 2004 |
All India Secondary School Examination (Class X) |
| BOARD |
Central Board of Secondary Education |
| SCHOOL |
Delhi Public School, Kalyanpur, Kanpur, Uttar Pradesh, India |
| SUBJECTS |
English, Hindi, Mathematics, Science, Social Science and Introductory I.T. |
| MARKS OBTAINED |
84.5% |
|
|
| Research Experience |
| AUG. 2011 - JUL. 2012 |
"Quantitative Mueller matrix polarimetry with diverse applications" |
| SUPERVISOR |
Dr. Nirmalya Ghosh, Assistant Professor, Indian Institute of Science Education and Research, Kolkata, India. |
| JUN. - JUL. 2011 |
"Development and Eigenvalue calibration of an automated spectral Mueller matrix system for biomedical polarimetry" |
| SUPERVISOR |
Dr. Nirmalya Ghosh, Assistant Professor, Indian Institute of Science Education and Research, Kolkata, India. |
| MAY - JUL. 2010 |
"Theoretical study of Iron-based Superconductors" |
| SUPERVISOR |
Dr. Haranath Ghosh, Scientific Officer, Raja Ramanna Centre for Advanced Technology, Indore, India. |
| MAY - JUL. 2009 |
"Mueller Imaging: An approach to Detect Abnormality in Human Brain Tissues" |
| SUPERVISOR |
Prof. Asima Pradhan, Indian Institute of Technology, Kanpur, India. |
| JUN. - AUG. 2008 |
"To study the effect of ageing on the immune response in Drosophila melanogaster" |
| SUPERVISOR |
Dr. N.G. Prasad, Assistant Professor, Indian Institute of Science Education and Research, Kolkata, India. |
|
| Short Duration Interdisciplinary Projects |
| (Duration: 4 weeks approx.) Individual reports are published on www.scribd.com |
| APR. 2009 |
"Solitons & Base-pair Opening in DNA" |
| SUPERVISOR |
Prof. Prasanta K. Panigrahi, IISER-Kolkata. |
| APR. 2009 |
"Graph-theoretic approach to understand protein functioning using contact network" |
| SUPERVISOR |
Dr. Jayasri Das Sarma, Associate Professor, IISER-Kolkata. |
| APR. 2009 |
"A comparison between the enthalpies calculated using conventional methods and computational methods" |
| SUPERVISOR |
Prof. Sanjib Bagchi, IISER-Kolkata. |
| NOV. 2008 |
"To verify that the energy of the emitted photoelectrons is independent of the intensity of the light used in the photoelectric effect" |
| SUPERVISOR |
Dr. Bipul Pal, Assistant Professor, IISER-Kolkata. |
| NOV. 2008 |
"Identification and study of various local species of Drosophila" |
| SUPERVISOR |
Dr. N.G. Prasad, Assistant Professor, IISER-Kolkata. |
| NOV. 2008 |
"Estimation of chloride ion in plant leaves using fundamental principles of electro-chemistry" |
| SUPERVISOR |
Prof. Sanjib Bagchi, IISER-Kolkata. |
| APR. 2008 |
"To calculate the specific rotation for the mixture of two miscible liquids and establish a relation between the specific rotations of the two liquids and that of the mixture" |
| SUPERVISOR |
Prof. Swapan Kumar Dutta, IISER-Kolkata. |
| APRIL 2008 |
"Isolation & purification of bacteriophage particles from soil sample" |
| SUPERVISOR |
Prof. Tapas K. Sengupta, IISER-Kolkata. |
| APR. 2008 |
"Preparation & purification of racemic mixture of bi-naphthol and to confirm its structure and purity by NMR Spectroscopy" |
| SUPERVISOR |
Dr. Swadhin Mandal, Assistant Professor, IISER-Kolkata. |
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| Journal Publications |
| SEPT. 2012 |
"A comparative study of differential matrix and extended polar decomposition formalisms for polarimetric characterization of complex tissue-like turbid media" Satish Kumar, Harsh Purwar, Razvigor Ossikovski, I Alex Vitkin, Nirmalya Ghosh accepted for publication in Journal of Biomedical Optics. |
| |
Abstract: Development of methodologies for quantification / unique interpretation of the intrinsic polarimetry characteristics of biological tissues are important for various applications involving tissue characterization / diagnosis. We have performed a detailed comparative evaluation of the polar decomposition and the differential matrix decomposition of Mueller matrices for extraction / quantification of the intrinsic polarimetry characteristics (with special emphasis on linear retardance \(\delta\), optical rotation \(\psi\) and depolarization \(\Delta\) parameters, because these are the most prominent tissue polarimetry effects) from complex tissue-like turbid media exhibiting simultaneous scattering and polarization effects. The results suggest that for media exhibiting simultaneous linear retardance and optical rotation polarization events, the use of retarder polar decomposition with its associated analysis which assumes sequential occurrence of these effects, results in systematic underestimation of \(\delta\) and overestimation of \(\psi\) parameters. We have thus derived analytical relationships between the polarization parameters \((\delta,\psi)\) extracted from both the retarder polar decomposition and the differential matrix decomposition for either simultaneous or sequential occurrence of the linear retardance and optical rotation effects. The self-consistency of both decompositions is validated on experimental Mueller matrices recorded from tissue-simulating phantoms (whose polarization properties are controlled, known a-priori, and exhibited simultaneously) of increasing biological complexity. Additional theoretical validation tests were performed on Monte Carlo (MC)-generated Mueller matrices from analogous turbid media exhibiting simultaneous depolarization \((\Delta)\), linear retardance \((\delta)\) and optical rotation \((\psi)\) effects. After successful evaluation, the potential advantage of the differential matrix decomposition over the polar decomposition formalism was explored for monitoring of myocardial tissue regeneration following stem cell therapy. |
| JUN. 2012 |
"Elementary and collective excitations as probes for order parameter symmetry in Fe-based superconductors" Haranath Ghosh, Harsh Purwar Europhysics Letters, Vol. 98 Issue 57012. |
| |
Abstract: We show that the superconducting quasiparticle energy of Fe-based superconductors would be different for a sign-changing order parameter than that for a non-sign-changing order parameter. This particularly happens in the low-doping region when the electron and hole Fermi surfaces nest and superconductivity coexists with either magnetic or orbital or both density waves. This difference in the nature of superconducting quasiparticles is also detectable from collective mode excitations. We further show that while the magnetic spin density wave order competes with superconductivity, the orbital density wave grows when the superconductivity order parameter changes sign across the electron-hole Fermi surface. However, when the superconducting order parameter does not change sign both the density waves compete with superconductivity. Irrespective of the nature of the superconducting order parameter the spin and orbital density waves are concurrent indicating simultaneous magnetic and structural transition. The significance of the various results is discussed comparing the various experimental observations. |
| DEC. 2011 |
"Quantitative polarimetry of plasmon resonant spheroidal metal nanoparticles: A Mueller matrix decomposition study" Jalpa Soni, Harsh Purwar, Nirmalya Ghosh Optics Communications, Vol. 285 Issue 6, pp. 1599 - 1607. |
| |
Abstract: Quantitative polarization characteristics of plasmon resonant spheroidal metal (silver) nanoparticles are investigated using polar decomposition of scattering Mueller matrices. The decomposition analysis on the scattering matrices (computed using T-matrix approach) of preferentially oriented spheroidal silver nanoparticles showed enhanced linear retardance \((\delta)\) and diattenuation \((d)\) effects in their surface plasmon resonance bands, with intriguing spectral characteristics. While the magnitude of \(\delta(\lambda)\) peaked around the spectral overlap region of the transverse and the longitudinal dipolar plasmon resonance bands, \(d(\lambda)\) peaked at wavelengths corresponding to the peaks of these two bands. The observed linear retardance and diattenuation effects were attributed to the inherent differences in phases and amplitudes respectively, of the two orthogonal dipolar plasmon polarizabilities of the spheroidal metal nanoparticles, which were confirmed further by studying their angular dependence. Further, when averaged over all possible (random) orientation, addition of the individual retardance matrices having random orientation of axes manifests as stronger depolarization \((\Delta)\) in spheroidal metal nanoparticles as compared to their dielectric counterparts. Consequently, the spectral variations of \(\Delta(\lambda)\) for the randomly oriented nanoparticles resembled that for the variation of \(\delta(\lambda)\) for the preferentially oriented ones. Derivation, quantification and unique interpretation of the intrinsic plasmon polarization characteristics (and their spectral behaviour) aided by Mueller matrix decomposition may have important implications for contrast enhancement in nanoparticle-based biomedical imaging, as well as in other applications involving nano-plasmonics. |
| SEP. 2011 |
"Differing self-similarity in light scattering spectra: A potential tool for pre-cancer detection" Sayantan Ghosh, Jalpa Soni, Harsh Purwar, Jaidip Jagtap, Asima Pradhan, Nirmalya Ghosh, Prasanta K. Panigrahi Optics Express, Vol. 19 No. 20, pp. 19708 - 16. Selected for further impact by Virtual Journal for Biomedical Optics, Vol. 6 Issue 10, Nov. 2011. |
| |
Abstract: The fluctuations in the elastic light scattering spectra of normal and dysplastic human cervical tissues are analysed through wavelet transform based techniques revealing clear signatures of self-similar behaviour in the spectral fluctuations. The values of the scaling exponent observed for these tissues indicate differences in the self-similarity for dysplastic tissues and their corresponding normal (healthy) tissues. The strong dependence of elastically scattered light on the size distribution of the scatterers manifests in the angular variation of the scaling exponent. Interestingly, the spectral fluctuations in both these tissues showed multi-fractality (non-stationarity in fluctuations), the degree of multi-fractality being marginally higher in the case of dysplastic tissues. These findings using the multi-resolution analysis capability of the discrete wavelet transform can contribute to the recent surge in the exploration for non-invasive optical tools for pre-cancer detection. |
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| Conference Proceedings |
| JUL. 2012 |
"Orbital density wave, spin density wave and superconductivity in Fe-based materials" Haranath Ghosh, Harsh Purwar AIP Conference Proceedings, Volume 1461, pp. 328-331. |
| |
Abstract: Using the two-band model, we study the interplay among orbital density wave, spin density wave and superconductivity in Fe based materials. The susceptibilities corresponding to orbital modulation and inter orbital spin density show enhanced peak at around the nesting wave vector indicating the possibility of respective density waves. It is shown that both the orbital and spin density waves are concurrent and irrespective of their zero temperature magnitudes, they have the same transition temperature. Superconductivity is studied in three scenarios - intra, inter and a mixed inter-intra orbital pairing scenarios. Inter orbital pairing is found to be dominant whereas mixed inter-intra orbital pairing scenario provides higher \(T_{c}\). The \(S^{\pm}\) wave superconductivity is found to be most stable within the model. |
| JAN. 2012 |
"Development and Eigenvalue calibration of an automated spectral Mueller matrix system for biomedical polarimetry" Harsh Purwar, Jalpa Soni, Harshit Lakhotia, Shubham Chandel, Chitram Banerjee, Nirmalya Ghosh Proc. of SPIE, Vol. 8230 No. 823019. |
| |
Abstract: We present a novel spectral Mueller matrix measurement system for both elastic and inelastic scattering (fluorescence) polarimetric measurements. The system comprises of a Xenon lamp as excitation source, a polarization state generator (PSG) and a polarization state analyzer (PSA) unit to generate and analyze polarization states required for \(4 \times 4\) sample Mueller matrix measurements, coupled to a spectrometer for spectrally resolved (\(\lambda \sim 400 - 800\) nm) signal detection. The PSG unit comprises of a fixed linear polarizer (polarization axis oriented at horizontal position) followed by a rotatable broadband quarter wave plate. The sample-scattered light is collected and collimated using an assembly of lenses, then passes through the PSA unit, and is finally recorded using the spectrometer. The PSA unit essentially consists of a similar arrangement as that of the PSG, but positioned in reverse order, and with the axis of the linear polarizer oriented at vertical position. A sequence of sixteen measurements are performed by changing the orientation of the fast axis of the quarter wave plates of the PSG unit (for generating the four required elliptical polarization states) and that of the PSA unit (for analyzing the corresponding polarization states). The orientation angles \((35^{\circ}\), \(70^{\circ}\), \(105^{\circ}\), \(140^{\circ})\) were chosen based on optimization of the PSG and PSA matrices to yield most stable system Mueller matrices. The performance of the polarimeter was calibrated using Eigenvalue calibration method which also yielded the actual values of the system PSG and PSA matrices at each wavelength. The system has been automated and is capable of Mueller matrix measurement with high accuracy over the entire spectral range 400 - 800 nm (elemental error < 0.01). For recording the elastic scattering Mueller matrix of sample, the PSG and PSA matrices for each wavelength are used, while for fluorescence Mueller matrix measurements, the PSG for the excitation wavelength (chosen to be 405 nm) and PSA for varying emission wavelengths (450 - 800 nm) are used. The developed spectral Mueller matrix system has been initially used to record both elastic scattering and fluorescence Mueller matrices from normal and cancerous cervical tissues. |
| NOV. 2011 |
"Enhanced polarization anisotropy of metal nano-particles and their spectral characteristics in the surface plasmon resonance band" Jalpa Soni, Harsh Purwar, Nirmalya Ghosh appeared in paper version of Proc. of SPIE, Vol. 8096 No. 809624. |
| |
Abstract: The spectral and angular polarization characteristics of spheroidal metal (silver) nanoparticles in their surface plasmon resonance spectral region were investigated using the T-matrix approach for light scattering in combination with a polar decomposition method. The decomposition of the T-matrix-computed scattering matrices for preferentially oriented silver nanoparticles yielded interesting spectral characteristics of the derived linear retardance (\(\delta\), phase difference between orthogonal linear polarizations) parameter, the values for \(\delta(\lambda)\) peaking around the spectral overlap region (380 - 420 nm) of the longitudinal and the transverse dipolar plasmon resonance bands. The variations of the derived scattering-induced diattenuation (\(d\), differential attenuation of orthogonal polarization states) also showed distinct spectral characteristics, \(d(\lambda)\) peaking at wavelengths corresponding to the peaks of the two orthogonal dipolar plasmon bands. The observed linear retardance and diattenuation effects were attributed to the differences in phases and amplitudes respectively, of the longitudinal and the transverse dipolar plasmon polarizabilities of the spheroidal metal nanoparticles. The analysis also showed that when averaged over all possible orientation of the particles (for randomly oriented spheroids), the strong retardance effects of individual nanoparticles manifests as stronger depolarization (\(\Delta\)) of light in spheroidal metal nanoparticles as compared to their dielectric counterparts. |
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| Poster Presentations |
| FEB. 2012 |
"Development and Eigenvalue calibration of an Automated Spectral Mueller Matrix Measurement System" Harsh Purwar, Jalpa Soni, Harshit Lakhotia, Uday Kumar, Ayan Banerjee, Nirmalya Ghosh presented at `Inter-IISER Physics Meet' organized by Indian Institute of Science Education and Research, Kolkata, India. |
| DEC. 2011 |
"Orbital density wave, inter-orbital spin density wave and inter-orbital superconductivity in Fe-based materials" Haranath Ghosh, Harsh Purwar presented at `International Workshop on Functional Materials' organized by National Institute of Science and Technology, Berhampur, Orissa, India in association with Drexel University, Philadelphia, USA. |
| JUN. 2011 |
"Automated Spectral Mueller Matrix Polarimeter" Harsh Purwar, Jalpa Soni, Harshit Lakhotia, Shubham Chandel, Chitram Banerjee, Nirmalya Ghosh presented in a workshop on `Trends in Optics' at S.N. Bose National Centre for Basic Sciences, Kolkata, India. |
|
| Contribution in Other Posters |
| FEB. 2012 |
"Light Scattering from Self-Affine Structures: Potential Applications" Nandan Kumar Das, Subhasri Chatterjee, Satish Kumar, Harsh Purwar, Jalpa Soni, Nirmalya Ghosh, Prasanta K. Panigrahi presented at `Inter-IISER Physics Meet' organized by Indian Institute of Science Education and Research, Kolkata, India. |
| FEB. 2012 |
"Differential Matrix Formalism and Inverse Mueller Matrix Polarimetry" Satish Kumar, Harsh Purwar, Razvigor Ossikovski, I Alex Vitkin, Nirmalya Ghosh presented at `Inter-IISER Physics Meet' organized by Indian Institute of Science Education and Research, Kolkata, India. |
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| Computer Skills |
| OPERATING SYS. |
Microsoft Windows (7, Vista, XP) and Linux (Ubuntu, Debian, OpenSuse, Fedora). |
| PROGRAMMING LANGS. |
Fortran, C++, Java. |
| SCRIPTING LANGS. |
MATLAB, Python, LaTeX, Linux Shell, PERL, PHP and HTML. |
| SOFTWARES |
LabView, Corel Graphics Suite and Microsoft Office. |
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| Achievements and Awards |
| 2007 2012 |
Awarded Inspire Fellowship by the Department of Science and Technology, India. |
| MAR. 2012 |
General Graduate Record Examination (GRE) 312 out of 340 (Verbal Reasoning: 147/170, Quantitative Analysis: 165/170). |
| MAR. 2012 |
Test of English as a Foreign Language (TOEFL) 91 out of 120. (Reading: 16/30, Listening: 26/30, Speaking: 24/30, Writing: 25/30). |
| MAR. 2012 |
Qualified Graduate Aptitude Test in Engineering (GATE) - 95.42 percentile. |
| JUN. JUL. 2010 |
Awarded Summer Research Fellowship and Travel Grant by Department of Atomic Energy during an internship at Raja Ramanna Centre for Advanced Technology, Indore, India through Young Scientist Research Programme (YSRP). |
| 2005 (CLASS XI) |
Stood first in my class in National Informatics Olympiad organized by Silver Zone, New Delhi, India. |
| JAN. 2003 (CLASS IX) |
Qualified National Level Science Talent Search Examination. |
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Extracurricular Activities and Interests |
- Play Table Tennis, Volley Ball, Chess, Basketball and Badminton fairly well.
- Active member of IISER-K Nature Club.
- Participated in Debugging Event at Comfest 2005, organized by Jaipuria Computer Club held at Seth Anandram Jaipuria School, Kanpur, India.
- Participated in Inter School Competition on Software at International Conference & Exposition on Communications and Computing held at Indian Institute of Technology, Kanpur, India in Feb. 2005.
- Participated in Surprise Event at Comfest 2004, organized by Jaipuria Computer Club held at Seth Anandram Jaipuria School, Kanpur, India.
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| References |
| NAME |
Prof. Prasanta K. Panigrahi |
| DESIGNATION |
Professor |
| INSTITUTE |
Indian Institute of Science Education and Research, Kolkata, India |
| EMAIL ID |
pprasanta@iiserkol.ac.in |
| NAME |
Prof. Narayan Banerjee |
| DESIGNATION |
HOD, Physical Sciences |
| INSTITUTE |
Indian Institute of Science Education and Research, Kolkata, India |
| EMAIL ID |
narayan@iiserkol.ac.in |
| NAME |
Dr. Nirmalya Ghosh |
| DESIGNATION |
Assistant Professor |
| INSTITUTE |
Indian Institute of Science Education and Research, Kolkata, India |
| EMAIL ID |
nghosh@iiserkol.ac.in |