Enhanced sensitivity operation of an optical gyroscope near an exceptional point

TL;DR

This paper demonstrates over four times enhancement in rotation sensitivity of a chip-based optical gyroscope by operating near an exceptional point, revealing new physics and potential for advanced sensing applications.

Contribution

The study experimentally shows sensitivity enhancement near an exceptional point in a chip-based gyroscope, linking non-Hermitian physics with practical sensing improvements.

Findings

Over 4X boost in rotation sensitivity near an exceptional point

Identification of a second-order EP from dissipative coupling

Modeling confirms the experimental sensitivity enhancement

Abstract

Exceptional points (EPs) are special spectral degeneracies of non-Hermitian Hamiltonians governing the dynamics of open systems. At the EP two or more eigenvalues and the corresponding eigenstates coalesce. Recently, it has been proposed that EPs can enhance the sensitivity of optical gyroscopes. Here we report measurement of rotation sensitivity boost by over 4X resulting from operation of a chip-based stimulated Brillouin gyroscope near an exceptional point. A second-order EP is identified in the gyroscope and originates from the dissipative coupling between the clockwise and counterclockwise lasing modes. The modes experience opposing Sagnac shifts under application of a rotation, but near the exceptional point new modal admixtures dramatically increase the Sagnac shift. Modeling confirms the measured enhancement. Besides the ability to operate an optical gyroscope with enhanced sensitivity, this result provides a new platform for study of non-Hermitian physics and nonlinear optics with precise control.