Toward two-color intensity squeezing at telecom wavelength using FWM in Rb vapor

We explore the Four-Wave Mixing (FWM) process in hot Rubidium vapor utilizing a 4-level double-ladder system, driven by two intense pump fields to excite Rb85 to the 6S1/2 state, since such system enables generation of a bi-chromatic quantum-correlated optical fields. Since one of the fields falls into the telecom bandwidth and the other is resonant with atoms, this becomes a promising resource for long-distance entanglement distribution between local atom-based quantum nodes. In our experiment, we achieve amplification of a weak 795nm seed field and the generation of a new 1324nm field via FWM gain in Rb85 vapor. Operating at 87°C, we achieve up to 240% amplification of the weak seed field into the generated telecom field, and observe overall transmission rate exceeding 70% for the amplified seed field. Preliminary experimental results for the two-mode intensity noise measurements are also presented.