Dr. Parinda Vasa
Date of Birth: 6th May 1977
Optical and Near-field spectroscopy, Optical properties of semiconductors nanoparticles
- Aug. 06 – Present, Alexander von Humboldt fellow in the group of Prof. Christoph Lienau at Carl von Ossietzky University, Oldenburg, Germany.
- Jan. 06 – Jul. 06, Short-term visitor at Prof. Martin Wegener’s group at Institute fur Angewandte Physik, University of Karlsruhe, Germany.
- Aug. 99 – Dec. 05, Ph.D. (Physics), Dept. of Condensed Matter Physics & Materials Science, Tata Institute of Fundamental Research (TIFR), Mumbai, India, Thesis advisor: Prof. Pushan Ayyub.
- Jul. 97 – Jul. 99, M.Sc., Physics with First Class, Indian Institute of Technology Bombay, Powai, Mumbai – 400076, India.
- Jul. 94 – Jul. 97, B.Sc., Physics and Instrumentation with First Class, Jai Hind College, Mumbai University, Mumbai – 4000020, India.
Alexander von Humboldt fellow (postdoctoral fellow) in the group of Prof. Christoph Lienau at Carl von Ossietzky University, Germany.
Nature of Duties
The proposed research of the fellowship program in the field of plasmonics and near-field spectroscopy will be performed in collaboration with the groups of Prof. Christoph Lienau at Carl von Ossietzky University, Germany and Prof. Erich Runge at Institute of Physics, Technical University, Ilmenau, Germany.
Optical devices based on Surface Plasmon Polaritons (SPPs) have the tremendous advantages of miniaturized configuration and potential of parallel processing. Therefore it is interesting to study the propagation properties of SPPs in ordered and disordered metallic nano-structures. In analogy to photonic crystals, in plasmonic crystals also the radiative losses can be tailored and dispersion relations can be manipulated by changing the size, shape and density of the holes or the slits. However, the major drawback of these structures is the small SPP propagation length which can be enhanced either by coupling different SPP modes or by SPP amplification. SPP amplification in metal-semiconductor hybrid structures is very promising for basic studies as well as from device point of view. A particularly intriguing concept is that of Surface Plasmon Amplification using Stimulated Emission of Radiation (SPASER) and a key to the understanding and designing of SPASER structures is understanding the optical properties of the SPP eigenmodes in disordered plasmonic structures.
So far, SPP amplification at IR and visible wavelengths has been only theoretically predicted. Therefore we will be investigating the coupling between different SPP modes in metal-semiconductor hybrid structures to explore the possibility of SPP amplification using optical or electrical pumping. Coupling between SPPs and other material excitations like excitons will be studied experimentally as well as theoretically and the possibility of forming different active and passive optical elements based on metal-semiconductor hybrid structures will be explored.
Hobbies: Wildlife and bird watching, drawing and painting, anything that involves colors.
About my stay in Germany:
I am very happy to have got an opportunity to spend some time in Germany in particular at Oldenburg. What I like the most here is the culture: Modern yet traditional. I also find people very friendly and helpful. I am very thankful to all my group members for making me feel at home. It is a very different experience living here as so far I lived in Bombay which is a much bigger and crowded city.
Yet I do miss India and my people. It gets lonely at times but I like this place and would certainly be visiting many times in future.
- Humboldt Fellowship of Alexander von Humboldt Foundation, Germany for conducting research at Technical University of Ilmenau, Germany in collaboration with Prof. Christoph Lienau and Prof. Erich Runge (2006).
- Best thesis award given by Indian Physics Association and Department of Atomic Energy, Government of India during Golden Jubilee Solid State Physics Symposium, Bhabha Atomic Research Center, India (2005).
- Department of Condensed Matter Physics and Materials Science Grant for visiting Max Planck Institute of Biochemistry, Martinsried, Germany for period of six weeks and to attend 7th International Conference on Nano-Structured Materials-2004, Wiesbaden Germany (2004).
- Department of Science and Technology, Government of India award for attending the meeting with the Nobel Laureates in Physics, Lindau, Germany (2004).
- Second prize in Indian Physical Society Young Physicist Colloquium (Award), Kolkata, India (2004).
- Sarojini Damodaran International Fellowship (TIFR) for visiting University of Iowa and University of Michigan, USA for period of three months (2003).
- Council for Scientific and Industrial Research, India Foreign Travel Grant for Young Scientist/Research Scholar for attending CLEO/QELS-2003, Baltimore USA and presenting two papers (2003).
- New Focus Travel Grant (Optical Society of America) for presenting two papers at CLEO-2003 (2003).
Publications in Journals
- Vasa P., Singh BP. and Ayyub P., Nonlinear photoresponse in II-VI-based nanocomposite thin films: A semi-quantitative four-level model, Journal of Optical Society of America B, 23, 692, 2006.
- Bose S., Raychaudhuri P., Banerjee R., Vasa P. and Ayyub P., Mechanism of the size dependence of superconductivity in nanocrystalline Nb, Physical Review Letters, 95, 147003, 2005.
- Vasa P., Singh BP. and Ayyub P., Fast and reversible excited state absorption in II-VI-based nanocomposite thin films, Applied Physics Letters, 87, 063104, 2005.
- Ayyub P., Vasa P., Taneja P., Banerjee R. and Singh BP., Photoluminescence enhancement in nanocomposite thin films of CdS-ZnO, Journal of Applied Physics, 97, 104310, 2005 (also to appear in the Virtual Journal of nanotechnology).
- Mishra SN., Bose S., Vasa P., Ayyub P., Size effects on the local magnetism and Kondo behavior of isolated Fe impurities in nanocrystalline metallic hosts, Physical Review B, 71, 094429, 2005.
- Vasa P., Singh BP. and Ayyub P., Coherence properties of photoluminescence from CdS:ZnO nanocomposite thin films, Journal of Physics Condensed Matter, 17, 189, 2005.
- Vasa P., Rajeev PP., Ravindra KG., Singh BP. and Ayyub P., Nonlinear optical properties of nanocrystalline thin films, Transactions of Material Research Society of Japan, 29, 47, 2004.
- Vasa P., Singh BP., Taneja P. and Ayyub P. Antiresonant ring interferometry as a sensitive technique for measuring nonlinear optical properties of thin films, Optics Communications, 233, 297, 2004, Erratum: 237, 451, 2004.
- Banerjee R., Vasa P., Thompson GB., Fraser HL. and Ayyub P., Proximity effect in Nb/Zr multilayers with variable Nb/Zr ratio, Solid State Communications, 127, 349, 2003.
- Vasa P., Taneja P., Ayyub P., Sing BP. and Banerjee R., Photoconductivity in sputter deposited CdS and CdS:ZnO nanocomposite thin films, Journal of Physics Condensed Matter, 14, 281, 2002.
- Taneja P., Vasa P. and Ayyub P., Chemical passivation of sputter deposited nanocrystalline CdS thin films, Materials Letters, 54, 343, 2002.
Papers Presented in Conferences
- Runge E., Schwieger S. and Vasa P., Surface-plasmon-polariton band structure of nanostructured multi-layer systems, Proceedings of American Physical Society March Meeting 2007, USA.
- Schwieger S., Runge E., and Vasa P., Coupling phenomena of surface plasmons, Proceedings of German Physical Society Spring Meeting, 2007, Germany.
- Rand SC., Li B. and Vasa P., Coherence experiments in a random, color center laser system, Proceedings of Conference on Lasers and Electro-Optics 2004, USA.
- Vasa P., Singh BP., Taneja P., Banerjee R. and Ayyub P., Enhanced photoluminescence from CdS:ZnO nanocomposite thin films, Proceedings of Conference on Nanoscience and Technology, Nano 2004, Germany.
- Bose S., Banerjee R., Vasa P., Raychaudhury P. and Ayyub P., Finite size effects in nanocrystalline thin films of Nb, International Conference on Nanoscience and Technology-2003, India.
- Vasa P., Singh BP., Taneja P. and Ayyub P., Photoluminescence properties of CdS:ZnO nanocomposite thin films, Proceedings of Conference on Lasers and Electro-Optics 2003, USA.
- Vasa P., Singh BP., Taneja P. and Ayyub P., Dispersion of two-photon coefficient in sputter deposited CdS:ZnO nanocomposite thin films, Proceedings of Conference on Lasers and Electro-Optics 2003, USA.
- Vasa P., Singh BP., Taneja P. and Ayyub P., Measurement of nonlinearity in thin films using Anti Resonant Ring Interferometer, Proceedings of Photonics-2002, India.
- Vasa P., Singh BP., Taneja P. and Ayyub P., Measurement of diffusion length in CdS:ZnO nanocomposite thin film using photocarrier grating technique, Proceedings of National Laser Symposium-2001, India.
- Vasa P., Singh BP., Taneja P. and Ayyub P., Mid – bandgap photoconductivity in sputter deposited CdS-ZnO nanocomposite thin films, Proceedings of National Laser Symposium 2001.
- Vasa P., Singh BP., Taneja P. and Ayyub P., Large nonlinear optical response of CdS-ZnO nanocomposite thin films, Proceedings of National Laser Symposium 2001.
- Singh B. P., Kundu T., Chatterjee S. and Vasa P., Second molecular hyperpolaizability of inorganic mixed metal clusters, Proceedings of National Laser Symposium 2001.
- Singh B. P., Kundu T. and Vasa P., Nature of Two-photon resonant nonlinearity of fluorecein doped boric acid glass, Proceedings of National Laser Symposium 2001.
- Vasa P. and Singh BP., Non-critical non-collinear phase matching for amplification of femtosecond pulses, Proceedings of National Laser Symposium-1999, India.