Kerr-based non-Hermitian optical gyroscope leveraging unbalanced coupling

The interest in non-Hermitian sensing has gained renewed attention after the demonstration of the increased signal-to-noise ratio of exceptional-point (EP)-based sensors. Here, we investigate a non-linear non-Hermitian gyroscope based on Kerr nonlinearity. This novel, to the best of our knowledge, architecture is based on the induced unbalanced coupling between the counterpropagating modes in the resonator, which enables the presence of an EP at rest without the need for any bias angular velocity. With respect to previous works, here we demonstrate that the EP appears on the optical power spectrum, corresponding to the bifurcation point of the spectrum of the nonlinear sensor. The possibility of inducing an EP in a single resonator could benefit from a reduced risk of unpredictable perturbation effects. Furthermore, we show that the EP can be induced even in the absence of a bias rotation by means of the tuning of the input power.