Quantum noise in parametric amplification under phase-mismatched conditions

•Quantum noise in phase-mismatched parametric amplification is investigated.•Equations for the field operators phase-mismatch are derived.•It is shown that NF degrades with phase-mismatching in phase-sensitive amplification.

This paper studies quantum noise in parametric amplification under phase-mismatched conditions. The equations of motion of the quantum-mechanical field operators, which include phase mismatch under unsaturated conditions are first derived from the Heisenberg equation. Next, the noise figure is evaluated using the solutions of the derived equations. The results indicate that phase mismatch scarcely affects noise property in phase-insensitive amplification while it has a notable effect in case of phase-sensitive amplification.