In this manuscript, we discuss the performance of a recently demonstrated polarization-based truncated SU(1,1) interferometer1 which can potentially generate polarization-entangled twin beams for applications in quantum communications or in quantum metrology as an interferometer with enhanced phase sensitivity. Using the intensity-squeezed twin beams generated via four-wave mixing (FWM) in hot Rubidium vapor, we report the detection of nearly -2 dB of noise reduction below the shot-noise in the joint-quadrature measurements in such interferometer. We also used this setup to confirms the non-classical nature of quantum correlations between the twin beams with an inseparability parameter I = 1:32±0:04 that falls below the classical limit of 2. One of the important advantages of the proposed interferometer is its better rejection of common-mode, technical, and environmental noises due to its intrinsic symmetry, which allows for squeezing and entanglement measurements at wide spectrum of detection frequencies from as low as 200 Hz (limited by 1=f electronic noise) to up to a few MHz (limited by the photodetector gain bandwidth).
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