Experimental generation of 6 dB continuous variable entanglement from a nondegenerate optical parametric amplifier
Yu Wang, Heng Shen, Xiaoli Jin, Xiaolong Su, Changde Xie, Kunchi Peng · Optics Express · 2010
We experimentally demonstrated that the quantum correlations of amplitude and phase quadratures between signal and idler beams produced from a non-degenerate optical parametric amplifier (NOPA) can be significantly improved by using a mode cleaner in the pump field and reducing the phase fluctuations in phase locking systems. Based on the two technical improvements the quantum entanglement measured with a two-mode homodyne detector is enhanced from approximately 4 dB to approximately 6 dB below the quantum noise limit using the same NOPA and nonlinear crystal.