I’m Bikash Kumar Das, a researcher in the faculty of Physics at Technion-Israel Institute of Technology, Israel. My current research is on generating attosecond optical pulses using a novel mechanism, popularly known as high harmonic generation (HHG). HHG is a nonlinear process (in the non-perturbative regime) that allows the interaction of short (few cycles pulses of duration in the femtosecond regime)& intense (>10^13 W/cm^2) optical pulses with the atom(s) such as He, Ne, Ar, Xe, etc. (in the gas cell or gas jet), molecules, plasma, solids (crystals, nanostructures). Noble gases are mostly used in the case of gas phase HHG due to their high damage threshold and binding energy. HHG is a source of coherent extreme ultraviolet (EUV) and Soft X-ray radiation. Light bursts with attosecond duration are the shortest man-made event known to the world to date, though generating Zeptosecond (1 zs=10^-21 s) and Yoctosecond bursts is feasible but it requires relativistic driving laser intensity (>10^18 W/cm^2) which is not readily available with the current Lasers, However it may possible to generate these extremely short bursts in future with free electron lasers (FEL) . Attosecond pulses find applications in many areas such as (1) probing dynamics of the electrons in atoms/molecules (2) probing biomolecular interactions (protein-protein) in living organisms (3) probing nuclear dynamics (4) attosecond spectroscopy (5) studying the charge migration in chemical reactions (6) communication . I’m
working on both gas & solid phase HHG. One of my research objectives is to reduce the pulse duration of an attosecond pulse to the atomic unit of time (24 as).Currently, the duration of the shortest attosecond pulse is 43 as. I’m also working on reducing the phase mismatch in the HHG medium using a novel technique that leads to the enhancement of harmonic yield (or, efficiency). We are also working on generating HHG from quasi-crystals(QCs) using transmission and reflection geometry. My previous research works were on (a) generating optical phase singular beams (both scalar & vector vortex beams) and propagating those beams for communication applications (b) generating polarization entangled photons through spontaneous parametric down conversion (SPDC) and their use in free space and fiber based quantum key distribution (QKD) (c) quantum random number generator (QRNG) (d) quantum computing (QC) (e) Thin film deposition & characterization at Institute of Physics (IOPB), Utkal University- TIFR, Defence Research & Development Organization (DRDO) . I’ve done these research works under different bodies of Government of India such as Department of Atomic Energy (DAE), Science and Engineering Research Board (SERB-DST), Department of Space (DoS) & Ministry of Defence (MoD). I’m also working on a study of correlation between Game Theory and Quantum Mechanics with Prof. Robert J. Aumann (2005 Nobel laureate for Game Theory) and Prof. Adam Brandenburger (Distinguished Prof. at NYU,USA).