Toward bi-chromatic intensity squeezing at telecom wavelength using Four-Wave Mixing in Rb Vapor

In this study, we conduct experiments focusing on the generation of a two-color continuous variable(CV) entangled photon source, with one field in telecom wavelength while the other close to atomic transition,making it a promising platform for many quantum network applications. Specifically, we generate two correlated optical fields at 1367 nm and 795nm, respectively, through four-wave mixing (FWM) in a double-ladder four-level ⁸⁵Rb vapor. We achieved an off-resonance gain of 795nm field, reaching as high as 1.8 compared to the input seed, accompanied by a 73% optical transmission. Additionally, we presented preliminary evidence of intensity squeezing at -1dBm. Furthermore, we introduced several validated complementary methods that can be integrated to enhance the efficiency of photon generation. Our experiment serves as a proof of principle, showcasing the feasibility of extending bi-chromatic photon correlation into the continuous-variable (CV) regime.