Biomedical subjects

Chang-Yi Wang

Publications and source records attributed to Chang-Yi Wang.

3 recordsLinked to original sources

PubMed2006

Manipulating the retrieved frequency and polarization of stored light pulses.

We have experimentally demonstrated that stored and retrieved light pulses have different frequencies but maintain phase coherence; a stored light pulse is released with a different polarization. However, the manipulation process causes an energy loss of the retrieved pulse. We have discovered that Clebsch-Gordan coefficients among the Zeeman sublevels play an important role in the energy loss and have demonstrated a solution for avoiding the energy loss.

Journal Article↗

PubMed2006

Low-light-level all-optical switching.

We propose an all-optical switch that utilizes the technique of storage and retrieval of light pulses. A single photon (probe pulse) switched by another (switching pulse) is feasible, and the on-off ratio can be as large as 10 dB. We have experimentally demonstrated that the energy of the retrieved probe pulse is reduced to about 10% because of the presence of a switching pulse with an energy per unit area of one photon per lambda(2)/(2pi). The achieved result does not depend on the coupling intensity, the atomic optical density, or the width and shape of the switching pulse.

Journal Article↗

PubMed2006

Low-light-level cross-phase-modulation based on stored light pulses.

We experimentally demonstrate a low-light-level cross-phase-modulation (XPM) scheme based on the light-storage technique in laser-cooled 87Rb atoms. The proposed scheme can achieve a similar phase shift and has the same figure of merit as one using static electromagnetically induced transparency under the constant coupling field. Nevertheless, the phase shift and the energy loss of a probe pulse induced by a signal pulse are neither influenced by the coupling intensity nor by the atomic optical density in the light-storage XPM scheme. This scheme enhances the flexibility of the experiment and makes possible conditional phase shifts on the order of pi with single photons.

Journal Article↗