Vacuum fluctuations and the conditional homodyne detection of squeezed light
H. J. Carmichael, Hyunchul Nha · Journal of Optics B Quantum and Semiclassical Optics · 2004
Conditional homodyne detection of quadrature squeezing is compared with standard nonconditional detection. Whereas the latter identifies nonclassicality in a quantitative way, as a reduction of the noise power below the shot noise level, conditional detection makes a qualitative distinction between vacuum state squeezing and squeezed classical noise. Implications of this comparison for the realistic interpretation of vacuum fluctuations (stochastic electrodynamics) are discussed.