Toward bi-chromatic intensity squeezing using double-ladder four-wave mixing in 85Rb

We optimize the strength of the Four-Wave Mixing (FWM) in warm ⁸⁵Rb atoms in a double-ladder scheme to identify the optimal conditions for generating the bi-chromatic intensity squeezing. By optimizing the experimental parameters, such as laser frequency and intensity, cell temperature, beam geometry, etc., we achieved FWM gain up to 1.92 with only modest resonant optical losses, and observed some preliminary evidence of the noise correlations between the amplified probe and generated stokes optical field.