Robust Photon Transmission in Nonlinear Parity–Time‐Symmetric Cavities

We explore the photon transfer in nonlinear parity-time-symmetry system of two coupled cavities, which contains gain and loss dependent on intracavity photons. Analytical solution to steady state gives a saturated gain, satisfy parity-time symmetry automatically. The eigen-frequency self-adapts reach maximum efficiency state. find that weak coupling regime does not match state, exhibiting an appearance spontaneous symmetry-breaking. transmission parity-time-symmetric is robust against variation strength, improves results conventional methods by tuning frequency or strength maintain optimal efficiency. Our scheme provides experimental platform for realizing cavities with symmetry.