A study on stimulated emission from erbium in silicon

Prospects of stimulated emission from erbium in silicon have been analyzed by a Shockley–Read–Hall (SRH) model. A two-level system was considered for calculation of optical gain and the laser threshold. For an optical cavity of 300 μm with mirror reflectivities of 90% and an optimistic absorption coefficient of 5 cm−1, a population inversion of 1.4×1018 cm−3 was estimated as the threshold value. Achievement of the lasing condition was found feasible, but only for certain conditions of erbium activation. Non-radiative de-excitation routes were found to have strong influence on the erbium activity. On the assumption of 1019 cm−3 of optically active erbium sites with an overall spectral linewidth of 1 Å, linear increase of optical power in the laser cavity has been estimated for injected carrier densities above 1018 cm−3.