Ultrafast variable optical delay technique

We have demonstrated a new technique for achieving variable optical delay. Multiple copies of a dispersed optical pulse interfere and create an interference pattern in time. The central lobe may be time shifted by changing the optical phase relationship of the multiple copies of the dispersed pulse. The tuning speed is determined by the method used to induce the optical phase changes. The magnitude of the time tunability is determined by the amount of dispersion preceding the temporal grating generator. We believe this technique will have many important application areas, including optical networking and signal processing.