Anti-PT-symmetric Kerr gyroscope

Non-Hermitian systems can exhibit unconventional spectral singularities called exceptional points (EPs). Various EP sensors have been fabricated in recent years, showing strong spectral responses to external signals. Here we propose how to achieve a nonlinear anti-parity-time (APT) gyroscope by spinning an optical resonator. We show that, in the absence of any nonlinearity, the sensitivity or optical mode splitting of the linear device can be magnified up to 3 orders compared to that of the conventional device without EPs. Remarkably, the APT symmetry can be broken when including the Kerr nonlinearity of the materials and, as a result, the detection threshold can be significantly lowered, i.e., much weaker rotations which are well beyond the ability of a linear gyroscope can now be detected with the nonlinear device. Our work shows the powerful ability of APT gyroscopes in practice to achieve ultrasensitive rotation measurement.

Automated summary

This study proposes a method to achieve a nonlinear anti-parity-time (APT) gyroscope by spinning an optical resonator. The results show that, compared to conventional devices, the sensitivity or optical mode splitting of the linear device can be magnified up to three orders. When the Kerr nonlinearity of the materials is included, the nonlinear gyroscope can detect weaker rotations, significantly lowering the detection threshold.