Abstract:

The authors  experimentally demonstrated the optical information transfer between two frequencies channels based on electromagnetically induced transparency （EIT）  in a four level double lambda system in Pr∶YSO crystal. Under the conditions of EIT, a weak probe pulse is slowed during the propagation in the crystal. A group velocity of 86 m/s is observed experimentally. By adiabatically switching off the control field, most of the probe pulse is stored in the sample. By switching on two control fields （with distinct frequencies and direction）  in the release process, the stored optical information is distributed into two spatially\|separated channels from the original slow light pulse with a single channel.  By adjusting the two control fields in the release process, the information of slowed light pulse can be converted between the frequencies channels.

Key words: electromagnetically induced transparency, slow light, light storage, frequencies conversion