Two-beam Coupling Problem in Quantum Correlated Imaging
We generate bright, two-mode, intensity-difference squeezed light from four-wave mixing (4WM) in Rb vapor using Ti:Sapphire laser system. We achieve squeezing at frequencies below 10 Hz via dual-seeded 4WM. However, we notice that there is excess noise at low frequencies for the dual-seeded scheme due to the two-beam coupling mechanism. This noise can be avoided by making sure the two probe seeds do not intersect each other in the pump region. In our previous work of "Entangled Images from Four-Wave Mixing" we had similar “cross-talk” between the letters at low frequency. Based on the study of two-beam coupling mechanism, we know how to avoid the "cross-talk" problem in the quantum correlated imaging.
(pizza and drinks served 10 min. before talk)