Nonlinear interferometer based on two-port feedback nondegenerate optical parametric amplification

Abstract In this paper, we propose a nonlinear interferometer based on two-port feedback nondegenerate optical parametric amplification (NITFPA), which employs two linear beam splitters to feed the two output beams of a nondegenerate optical parametric amplifier back to its input ports. By comparing the NITFPA with the SU(1,1) interferometer (SUI), which is another typical nonlinear interferometer, we demonstrate that the NITFPA has its unique advantages in the precision enhancement of the phase estimation. In addition, we demonstrate that the NITFPA is also advantageous over the SUI in the robustness against the losses. Such a NITFPA may find its potential applications in quantum metrology.