Gain recovery acceleration in semiconductor optical amplifiers employing a holding beam

Experimental characterization of gain recovery is presented for a semiconductor optical amplifier saturated by a holding beam in co- and counter-propagating configurations at various wavelengths. The gain recovery is studied in detail for a holding beam at a wavelength near the gain transparency where an increase of the recovery time with the injected power is observed for the co-propagating configuration. The measurements confirm previous modelling results that are also used to explain this behaviour.