Demonstration of partial erasing of picosecond temporal optical data by use of accumulated photon echoes

Abstract

We demonstrated partial erasing of temporal optical data on a picosecond time scale by use of accumulated photon echoes. In a photon-echo memory the temporal data at time tau are stored as a frequency grating of period 1/tau in the absorption spectrum of a material. Partial erasing of the temporal data is achieved by irradiation of the material with a pulse pair at time separation tau , but the phase of one of the pulses is shifted 180 degrees . This process does not produce a frequency grating, and no echo is emitted. The experiment was performed with a dye-doped polymer film. The 180 degrees phase shift was obtained by use of a half-wave plate.