AMPLIFICATION OF MULTICOMPONENT SUPERPOSITIONS OF COHERENT STATES OF LIGHT WITH QUANTUM AMPLIFIERS

We analyze statistical properties of multicomponent superpositions of coherent states of light amplified by quantum-mechanical amplifiers wi th reduced quantum fluctuations. We show that sub-Poissonian (i.e., am plitude-squeezed) amplifiers can transform any initial superposition o f coherent states of light into a nonclassical state with a high degre e of sub-Poissonian photon statistics. Simultaneously the shape of the photon-number distribution of the initial state of light is preserved but shifted toward higher photon numbers. On the other hand, we show that phase-sensitive (i.e., quadrature-squeezed) amplifiers may preser ve the initial reduction of quadrature fluctuations (quadrature squeez ing). We show that by using amplifiers with reduced quantum noise one can, in principle, control the influence of the noise transferred from the amplifier to the system.