♦ Our experiments focus on ultrafast phenomena in atoms, molecules, clusters in the gas-phase as well as atoms, molecules and biological entities in the condensed phase.
* ultrafast laser pulses…they are “on” for only 5 fs: long enough for barely 2 optical cycles of 800 nm light!
* optical traps…using tightly focused laser beams to create a dipole trap…we work on LIVE single cells!
* spectroscopy integrated with traps…Raman Tweezers!
* time-of-flight spectrometry..”looking” at SINGLE ions!
* Infra-red & fibre lasers for photonics; nonlinear optics.
Some recent work :
*With only 2 optical cycles, the carrier envelope phase (CEP) within a pulse becomes important: we stabilize and control it!This allows us to explore how ionization and dissociation of molecules depend on CEP…opens new vistas for attosecond dynamics. [Mathur et al., Phys. Rev. Lett. 110 (2013) 083602]
*We’ve shown that ultrafast molecular rearrangements, like proton migration, can occur on timescales of only one vibrational period! [Garg et al., J. Chem. Phys. 136 (2012) 024320]
*By created hot plasma in water containing DNA we’ve shown that DNA damage can be induced by very low-energy electrons and by OH-radicals. [D’Souza et al., Phys. Rev. Lett. 106 (2011) 118101]
*We trap healthy and malaria-infected red blood cells to probe changes in cell membrane elasticity and birefringence.[Dharmadhikari et al., J. Biomed. Opt. 18 (2013) 125001]