Nonlinear optical absorption of beryllium isoelectronic centers doped in silicon waveguides

Impurities provide host materials with additional optical functionalities. In this study, we observed the nonlinear optical absorption of beryllium isoelectronic centers (Be-IECs) doped in silicon waveguides (WGs) with optical population control of their bound exciton states. The optimized fabrication based on ion implantation and rapid thermal annealing achieved Be-IEC doping with a high concentration. The bound exciton state localized at the doped Be-IECs shows a photoluminescence peak and optical absorption simultaneously at a wavelength of 1150 nm. Nonresonant optical pumping at a power of similar to 70 mu W reduces the optical absorption coefficient of a Be-doped WG by 1.3 cm(-1), which is one third of the intrinsic absorption. This significant reduction is attributed to the suppression of the absorption transition to the discrete bound exciton state filled by optical pumping. The nonlinear optical absorption of these impurity centers makes it possible to expand the potential application of Si-based photonic devices for enabling all-optical switching with lower optical power. Published by AIP Publishing.