Evaluation of free carrier losses to 1.54 μm emission in Si/Si:Er nanolayers on SOI substrate for optical gain observation

In this study we use a combination of variable stripe and shifting excitation spot methods to evaluate linear low temperature (4.2 K) optical properties of Si/Si:Er multinanolayer grown on SOI substrate. In particular, Er-1 luminescence at 1.54 μm under continuous wave excitation was examined. Absorption coefficients of 22.4 ± 4.2 and 45.1 ± 4.2 cm−1 at photon fluxes of 2.4 × 1019 and 2.4 × 1020 cm2 s−1, respectively, have been established. These are approximately three times higher than those found earlier for a similar structure grown on Si substrate.