Initially, my research interests were focused on processes with free electrons in strong laser fields. I proposed and investigated various optimized schemes of free electron lasers (FEL), such as cyclotron and Compton resonance in medium, surface Cherenkov process with unmagnetized beams, quantum nonlinear regime of FEL based on channeling radiation, coherent bremsstrahlung in a crystal. I also contributed to developing methods for treating electron nonlinear dynamics in strong fields, in particular, a new generalized eikonal approximation to treat the nonlinear relativistic quantum dynamics for potential scattering in a laser field, a multiphoton resonance approximation in strong fields. Among interesting results, I could mention the work on the stimulated bremsstrahlung during electron potential scattering in a high-frequency laser field where, surprisingly, a resonance effect arises. Important results include the clarification of the role of phase locking of the electron and laser waves to achieve electron beam modulation (classical or quantum-mechanical) in various stimulated processes.

During my work at the Institute for Applied Problems of Physics of the Armenian Academy of Sciences, I was involved in the investigation of the nonlinear behavior of low-temperature plasma in acoustic waves. In particular, I developed a theoretical model for acoustic flows in plasma which was successful in interpreting experimental results.

Later, since my work at Freiburg University, my interests have been shifted towards strong field atomic physics in relativistic regimes. High-order harmonic generation (HHG) when super-strong laser field propagates along and engulfes a micrometer thin crystal layer, a possibility for quasi-hase matching of HHG in periodic media, e.g. in crystal layers, have been considered. We have shown as well that HHG in relativistic domain can be achieved via a gas of positronium atoms and that strong laser fields can be emloyed to control positronium annihilation.