Optical Gain
Optical gain corresponds to a light-matter interaction regime for which generation of photons by stimulated emission dominates over photon absorption. As in other lasing media, optical gain in nanocrystals requires population inversion that is the situation in which the population of the excited states is larger than that of the ground state. Our activity is maily focused in the study of the feasibility of a first principles calculation of the optical gain, based on a detailed description of the system structure and electronic properties in the ground and in the excited states. Our approach uses ab-initio very accurate single particle wavefunctions as main ingredients for the construction of a correct excitonic manifold and the calculation of the relaxation time of the different decay processes.
Researchers:
Ivan Marri
Roberto Guerra
Marco Govoni
Scientific Highlights:
- Auger Recombination in Si and GaAs semiconductors: ab initio results
M. Govoni, I. Marri, S. Ossicini, submitted (2011)
Computational Packages:
Quantum Espresso
Yambo