We study the balanced-heterodyne detection of optical squeezing, for which the corresponding spectral density of
the photocurrent fluctuations produced at the output of the photo-detector is calculated as the Fourier transform
of their autocorrelation function. We show that, for maximal signal-to-noise ratio enhancement by use of squeezed
states of light, an optical signal to be measured in this scheme must be carried in the squeezed quadrature of
the carrier field. We discuss how this scheme may be exploited in gravitational-wave searching.