PT-symmetric systems can be used as ultrasensitive sensors by exploiting the non-Hermitian degeneracy at the exceptional point. However, operating and controlling these systems at the exceptional point are usually difficult. Here, we study the effect of rotation on threshold gain of circular Bragg lasers with radial PT symmetry. We have found that, even deviating away from the exceptional point, these lasers can provide two-orders-of-magnitude enhancement in the rotation sensitivity compared with the conventional circular Bragg lasers of similar geometry and threshold gain. Additionally, these lasers are more robust against perturbation in operating condition than sensors which must operate at the exceptional point.

中文翻译：

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𝒫𝒯对称圆形布拉格激光器极大地增强了旋转感应

通过在特殊情况下利用非Hermitian简并性，可以将PT对称系统用作超灵敏传感器。但是，通常很难在例外情况下操作和控制这些系统。在这里，我们研究旋转对具有径向PT对称性的圆形Bragg激光器的阈值增益的影响。我们发现，即使偏离最佳点，与具有类似几何形状和阈值增益的常规圆形布拉格激光器相比，这些激光器也可以在旋转灵敏度方面提供两个数量级的增强。另外，与必须在特殊点工作的传感器相比，这些激光器在工作条件下更能抵抗干扰。