  The sensitivity of the displacement transducer pumped with a train of
high-intensity laser pulses is estimated. Due to the multicomponent character
of the pump a consideration of transformations of the signal and the noises
between optical modes plays an important role in estimation of the potential
sensitivity. An expression for the minimal detectable external classical force
resembles those for the continuous wave pumping with substitution of the laser
power by a time averaged power of pulsed laser. Possible scheme for back action
noise compensation for such transducers is considered. For full suppression of
back action noise the field of local oscillator has to be pulsed with the same
time dependence as the pump field.
