We propose a new configuration for semiconductor optical amplifiers (SOAs), called optical speed-up at transparency (OSAT), which allows to speed up the gain recovery of SOAs and their saturation power without sacrificing the gain, nor increasing the applied current, The proposed configuration is particularly well-suited for high-speed WDM or OTDM applications, It consists of an optical cw-signal injected at the transparency point of the SOA, This setup is potentially integrable on a single chip, and still relatively flexible once the device is realized.