Dr Agarwal's work in optics and the master equation approach for laser theory have attracted international attention. His recent major contributions are in respect of the effect of temporal laser fluctuations on resonance fluorescence, theory of optical bistability, strong field effects on resonant Raman scattering and light scattering from rough surfaces. He has also contributed significantly to the quantum theory of optical Hanle Effect, subnatural line-width spectroscopy and to the theory of phase transitions in systems far from equilibrium.