Rotation sensing with PT-symmetric circular Bragg lasers

PT-symmetric optical systems can be used for unconventional control and manipulation of light. We designed chirped circular Bragg lasers with radial PT symmetry and analyzed their modal properties. Compared with the conventional circular Bragg lasers, PT-symmetric circular Bragg lasers possess more versatile modal control with further enhanced modal discrimination between the radial modes and between the azimuthal modes. PT-symmetric circular Bragg lasers also have advantages in rotation sensing by exploiting the effects of rotation on modal threshold gain. Their rotation sensitivity can be two orders of magnitude higher than that of conventional circular Bragg lasers with similar geometry and threshold gain. Additionally, they are more robust against perturbation induced by environmental variations than sensors that must operate at the exceptional point.