Professor: Indian Institute of Technology, Kanpur, India (2010-present).

Visiting Professor: Center for Bio-molecular Imaging, Duke University, NC, USA (Summer 2010).

Associate Professor: Indian Institute of Technology, Kanpur, India (2003-2010).

Visiting Professor: Center for Bits and Atoms, MIT, Cambridge, MA, USA (Summer 2002).

Fellow-E: Tata Institute of Fundamental Research, Mumbai (1998-2003).

Director of Laser Labs: CULA, Princeton University, Princeton, NJ, USA (1997-1998).

Senior Scientist (R&D): Quantronix Corporation, Hauppauge, NY, USA (1996-1997).

Research Associate: Brookhaven National Laboratory, Upton, NY, USA (1994-1996).

Post-Doctoral Fellow: Harvard University, Cambridge, MA, USA (1993-1994).

Research Assistant: Princeton Opto-Electronics & Materials Institute (POEM), Princeton University, Princeton, NJ, USA (1990-1993).

Computer System Administrator: Department of Computer Science, Princeton University, Princeton, NJ, USA (Spring 1992).

Industrial Researcher: J.T. Baker & Co. and Princeton University, Princeton, NJ, USA (Fall 1990).

Teaching Assistant: Department of Chemistry, Princeton University, Princeton, NJ, USA (1988-1990)

Summer Intern: Department of Physics, Indian Association for the Cultivation of Science, Calcutta, India (Summer 1987)