[1] P. R. Tapster, S. F. Seward, J. G. Rarity. Sub-shot-noise measurement of modulated absorption using parametric down-conversion. Phys. Rev. A, 1991, 44(5): 3266～3269

[2] J. J. Snyder, E. Giacobin, C. Fabre et al.. Sub-shot-noise measurement using the beat note between quantum-correlated phton beams. J. Opt. Soc. Am. B, 1990, 7(10): 2132～2136

[3] T. Debuisschert, S. Reynaud, A. Heidmann et al.. Observation of large quantum noise reduction using an optical parametric oscillator. Quant. Opt., 1989, 1(1): 3～9

[4] J. Mertz, T. Debuisschert, A. Heidmann et al.. Improvments in the observed intensity correlation of optical parametric oscillator twin beams. Opt. Lett., 1991, 16(16): 1234～1236

[10] S. F. Pereira, K. C. Peng, H. J. Kimble. Coherence and quantum optics Ⅳ. edited by J. H. Eberly, L. Mandel, E. Wolf, New York: Plenum, 1990. 889～891

[11] Z. Y. Ou, S. F. Pereira, E. S. Polzik et al.. 85% efficiency for cw frequency doubling from 1.08 to 0.54 μm. Opt. Lett., 1992, 17: 640～642

[12] A. Heidmann, R. J. Horowicz, S. Reynaud et al.. Observation of quantum noise reduction on twin laser beams. Phys. Rev. Lett., 1987, 59(22): 2555～2557