Using atomic motion to coherently spread light information stored in atoms provides a novel means to manipulate atom-light interactions. We demonstrate light splitting with moving atoms in a paraffin coated vapor cell, by using phase sensitive degenerate four wave mixing, or self-rotation. This scheme amplifies the beam splitter signal, and in the meantime maintains the phase coherence between the beam splitter channels. Light storage efficiency in the beam-splitting channel can be also enhanced. Such an amplified beam splitter should have applications in optical memory, optical routers and atomic coherence control.
"Slow and fast light in a phase sensitive system", Proc. SPIE 8998, Advances in Slow and Fast Light VII, 89980P (21 February 2014); doi: 10.1117/12.2047579; https://doi.org/10.1117/12.2047579