Debabrata Goswami

Our research focusses on Femtochemistry and experimental coherent control for spectroscopic enhancement. This program addresses fundamental aspects of laser-matter interactions with arbitrary pulse shaping. We investigate ultrafast laser pulse shaping applications in gaseous and liquid phase molecular dynamics, optoelectronics, nonlinear optics and optical communication, biologically relevant multi-photon fluorescence microscopy and optical trapping. These diverse fields have been knit together for quantum information processing. One of our approaches to exerting control over fundamental molecular processes has been in developing and exploring different control parameters that are systematically intrinsic: the environment around a molecule of interest plays a very important role. Molecules at the solid-liquid or liquid-liquid interface often behave in ways different from those observed in solution or in gas phase. Similarly, molecules under the influence of huge photon flux even at non-resonant interactive conditions behave distinctly. Likewise creating localized heating effects with femtosecond lasers gives rise to identifiable molecular signatures that have spectroscopic applications. We have also managed to show how to distinguish overlapping fluorophores in multiphoton imaging microscopy by exploiting repeated excitation and de-excitation processes with high repetitive rate femtosecond lasers. We have identified myriads of control parameters ranging from almost every laser parameter to the pH of the medium being studied. From conditions arising in optically designed environments, we show that a system's behaviour stems from its organization at nano-scales. With such levels of understanding of control, we plan to process information at molecular levels to facilitate quantum information processing. Thus the Goswami Group focusses on interdisciplinary areas of chemistry, biology and materials. A common region of interest in several of our programs is the interface between a material and a biological environment. We use programmable femtosecond laser pulses shaped to design and synthesize environments of our desired structures and properties. Hence the programs are adaptable to a large variety of problems addressing both fundamental and applied questions.