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Prashanth C Upadhya

Physics (University of Cambridge, UK, 2004)
Area of Interest:
Terahertz Spectroscopy, Ultrafast Phenomena in Condensed Matter and Nanophotonics
Email ID:
Research Interest:

The objective of our research is to develop and apply ultrafast optical tools that can temporally (at the fundamental timescale) as well as spatially resolve light-matter interaction over a broad wavelength range, from the visible to far infrared (Terahertz).  We employ tunable ultrafast lasers to develop novel ultrafast spectroscopy systems that can probe both static and non-equilibrium dynamics in variety of systems.

One of our research interests is in the area of terahertz science since terahertz (1012 Hz) radiation has immense scientific and technological importance because it embraces the fundamental interface between electronics and photonics. Our efforts are aimed at developing ultrafast terahertz sources and detectors, and implement them for variety of applications including spectroscopy, imaging and sensing.

Further, by employing variants of ultrafast techniques (for example, ultrafast microscopy) we study ultrafast carrier dynamics in nanostructured materials and explore new approaches to realize optimized functionalities of nanodevices for their application in nanophotonics and energy harvesting.

Academic Qualification:

PhD in Physics, Cavendish Laboratory, University of Cambridge, UK  (2004)


Assistant Professor, Department of Physical Sciences, IISER, Kolkata (2011 -     )

Research Fellow, Los Alamos National Laboratory (LANL), USA (2008 - 2011)

Post-doctoral Research Associate, University of Leeds, UK (2005 - 2007)

Awards and Honors:

BRNS (Board of Research in Nuclear Sciences, India) research fellowship (1997)

Commonwealth research scholarship offered by the Association of Commonwealth Universities in the UK (2001)

Academic Scholarship, Cambridge Philosophical Society, Cambridge, UK (2004)

List of Publications:
  1. Kar A, Li Q, Upadhya P C, Seo M A, Wright J, Luk T S, Wang G T, and Prasankumar R P (2012) The influence of radial heterostructuring on carrier dynamics in GaN nanowires, Appl. Phys. Lett. 101(14), 143104.
  2. Seo M A, Dayeh S A, Upadhya P C, Martinez J A, Swartzentruber B S, Picraux S T, Taylor A J and Prasankumar R P (2012) Understanding ultrafast carrier dynamics in single quasi-one-dimensional Si nanowires, Appl. Phys. Lett., 100, 071104.
  3. Upadhya P C, Li Q, Wang G T, Fischer A J, Taylor A J and Prasankumar R P (2010) The influence of defect states on non-equilibrium carrier dynamics in GaN nanowires (invited paper in special issue on nanowires), Semicond. Sci. Technol., 25, 024017.
  4. Dani K M, Ku Z, Upadhya P C, Prasankumar R P, Brueck S R J and Taylor A J (2009) Sub-picosecond optical switching with a negative index metamaterial, Nano Lett., 9(10), 3565-3569.
  5. Prasankumar R P, Upadhya P C and Taylor A J (2009) Ultrafast dynamics in semiconductor nanowires (invited feature article), Physica Status Solidi (b), 246(9), 1973-1995.
  6. Upadhya P C, Fan W, Burnett A, Cunningham J, Davies A G, Linfield E H, Lloyd-Hughes J, Castro-Camus E, Johnston M B and Beere H (2007) Excitation density dependent generation of broadband terahertz radiation in an asymmetrically-excited photoconductive antenna (selected for virtual journal), Opt. Lett., 32(16), 2297-2299.
  7. Cunningham J, Upadhya P C, Tiang C K, Lachab M, Khanna S, Linfield E H and Davies A G (2007) Monolithic integration of low-temperature-grown GaAs with a two-dimensional electron gas, Semicond. Sci. Technol., 22, 811–813.
  8. Fan W H, Burnett A, Upadhya P C, Cunningham J, Linfield E H and Davies A G (2007) Far-infrared spectroscopic characterization of explosives for security application using broadband terahertz time-domain spectroscopy, Appl. Spectrosc., 61(6), 638-643.
  9. Upadhya P C, Nguyen K L, Shen Y C, Obradovic J, Fukushige K, Griffiths R, Gladden L F, Davies A G and Linfield E H (2006) Characterization of crystalline phase-transformations in theophylline by time-domain terahertz spectroscopy, Spectrosc. Lett., 39(3), 215-224.
  10. Wood C D, Cunningham J, Upadhya P C, Linfield E H, Hunter I C, Davies A G and Missous M (2006) On-chip photoconductive excitation and detection of pulsed terahertz radiation at cryogenic temperatures, Appl. Phys. Lett., 88(14), 142103.
  11. Shen Y C, Upadhya P C, Linfield E H and Davies A G (2005) Observation of far-infrared emission from excited cytosine molecules, Appl. Phys. Lett., 87(1), 011105.
  12. Upadhya P C, Shen Y C, Davies A G and Linfield E H (2004) Far-infrared vibrational modes of polycrystalline saccharides, Vib. Spectrosc., 35(1-2), 139-143.
  13. Shen Y C, Upadhya P C, Beere H E, Linfield E H, Davies A G, Gregory I S, Baker C, Tribe W R and Evans M J (2004) Generation and detection of ultrabroadband terahertz radiation using photoconductive emitters and receivers, Appl. Phys. Lett., 85(2), 164-166.
  14. Shen Y C, Upadhya P C, Linfield E H, Beere H E and Davies A G (2004) Terahertz generation from coherent optical phonons in a biased GaAs photoconductive emitter, Phys. Rev. B, 69, Art. No. 235325.
  15. Shen Y C, Upadhya P C, Linfield E H, Beere H E and Davies A G (2003) Ultra-broadband terahertz radiation from low-temperature-grown GaAs photoconductive emitters, Appl. Phys. Lett., 83(15), 3117-3119.
  16. Shen Y C, Upadhya P C, Linfield E H and Davies A G (2003) Temperature-dependent low-frequency vibrational spectra of purine and adenine, Appl. Phys. Lett., 82(14), 2350-2352.
  17. Upadhya P C, Shen Y C, Davies A G and Linfield E H (2003) Terahertz Time-Domain Spectroscopy of Glucose and Uric Acid, J. Biol. Phys., 29(2-3), 117-121.