Quantized Optical Mode in a Phase-Switching Feedback Loop

摘要

We investigate the steady state of quantized monochromatic cavity mode excited by coherent pumping and placed in a feedback loop that changes the mode phase by pi upon each detection of the photon that left the cavity. Such type of feedback is used for fighting decoherence of Schrodinger cat states. Results of numerical calculations of the Glauber P-function for different detunings of mode frequency from pumping frequency are presented. Qualitative explanation for certain peculiarities of the behavior of the P-function is provided. We also suggest a simplified model that gives accurate description of the behavior of the system in the case where external coherent pumping is far detuned from the cavity eigenfrequency.