QUANTUM-NOISE REDUCTION IN LINEAR-AMPLIFIERS

It is proposed to produce phase sensitive amplification in two stages: (i) In the first stage, the ''preparation stage'', correlations betwe en pairs of different two-level atoms, which are initially in the uppe r or lower states, are produced by their interaction with two-mode squ eezed vacuum radiation. (ii) In the second stage, the ''amplification stage'', the correlated pairs of atoms from the first stage are insert ed in the linear amplifier where a phase sensitive amplification is ob tained. According to the analysis it is shown that significant quantum noise reduction can be obtained by using the present system.