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International Conference on Quantum Information

Experimental Generation of Broadband Quadrature Entanglement Using Laser Pulses

Yun Zhang, Ryuhi Okubo, Tatsuya Furuta, Takuya Hirano

Published Jan 1, 2007• 1 citation
Publisher

Abstract

We report the generation of broadband pulsed quadrature entanglement by combing two squeezed vacua with squeezing of 3.4±0.2 dB and bandwidth of 200 MHz, which are generated from two degenerate optical parametric amplifiers.
DOI
10.1364/icqi.2007.iff4

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We demonstrate the experimental generation of quadrature amplitude entanglement in the 1550 nm band by using a fiber optical parametric amplifier. The measured noise variances of the difference and sum of the quadrature amplitudes of the pulsed signal and idler twin beams fall below the shot noise limit by about 1 and 0.8 dB (4.2 and 3.6 dB after the correction for efficiency), respectively, showing that the inseparability criterion of Einstein-Podolsky-Rosen entanglement I<2 is satisfied. Our investigation reveals that the quality of the measured entanglement can be further improved by increasing the transmission efficiency of the twin beams and by optimizing the temporal mode matching of the two sets of homodyne detection systems.
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