  The ``optical springs'' regime of the signal-recycled configuration of laser
interferometric gravitational-wave detectors is analyzed taking in account
optical losses in the interferometer arm cavities. This regime allows to obtain
sensitivity better than the Standard Quantum Limits both for a free test mass
and for a conventional harmonic oscillator. The optical losses restrict the
gain in sensitivity and achievable signal-to-noise ratio. Nevertheless, for
parameters values planned for the Advanced LIGO gravitational-wave detector,
this restriction is insignificant.
