Schematic diagram of the experimental setup. The MZ interferometer with two input squeezed states consists of two PBSs, i.e., PBS1 and PBS2. The MZ interferometer with EPR entangled state consists of BS2 and another BS. OPA: optical parametric amplifiers; M1–M3: high-reflective mirrors; PZT: piezoelectric transducers; PBS: polarized beam splitters; HW: half wave plates; BS: 50% beam splitter; HD: balanced homodyne detectors; LO: Local oscillator; SA: Spectrum analyzer; OS: Oscilloscope; PM: phase modulator.