Exceptional points and the ring laser gyroscope

Abstract

An equivalence is made between the exceptional points proposed by the field of non-Hermitian quantum mechanics and the dead band observed in laser gyroscopes. The sensitivity enhancement near this exceptional point is plagued by increased uncertainty due to broadening of the beat-note bandwidth. Also, near the dead band the gyroscope response is caused by Rabi intensity oscillations and not solely by a phase modulation. Finally, a distinction is made between conservative and non-conservative coupling.