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Observation of the exceptional-point-enhanced Sagnac effect

Lai, Yu-Hung and Lu, Yu-Kun and Suh, Myoung-Gyun and Vahala, Kerry (2019) Observation of the exceptional-point-enhanced Sagnac effect. Nature, 576 (7785). pp. 65-69. ISSN 0028-0836. doi:10.1038/s41586-019-1777-z.

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Exceptional points (EPs) are special spectral degeneracies of non-Hermitian Hamiltonians that govern the dynamics of open systems. At an EP, two or more eigenvalues, and the corresponding eigenstates, coalesce. Recently, it was predicted that operation of an optical gyroscope near an EP results in improved response to rotations. However, the performance of such a system has not been examined experimentally. Here we introduce a precisely controllable physical system for the study of non-Hermitian physics and nonlinear optics in high-quality-factor microresonators. Because this system dissipatively couples counter-propagating lightwaves within the resonator, it also functions as a sensitive gyroscope for the measurement of rotations. We use our system to investigate the predicted EP-enhanced Sagnac effect and observe a four-fold increase in the Sagnac scale factor by directly measuring rotations applied to the resonator. The level of enhancement can be controlled by adjusting the system bias relative to the EP, and modelling results confirm the observed enhancement. Moreover, we characterize the sensitivity of the gyroscope near the EP. Besides verifying EP physics, this work is important for the understanding of optical gyroscopes.

Item Type:Article
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URLURL TypeDescription ReadCube access Paper
Lai, Yu-Hung0000-0002-9639-6569
Lu, Yu-Kun0000-0003-4840-0487
Suh, Myoung-Gyun0000-0002-9527-0585
Vahala, Kerry0000-0003-1783-1380
Alternate Title:Enhanced sensitivity operation of an optical gyroscope near an exceptional point
Additional Information:© 2019 Springer Nature Limited. Received 10 April 2019; Accepted 27 August 2019; Published 04 December 2019. We thank M. Khajavikhan, D. Christodoulides, O. Peleg and B. Loevsky for discussions during the preparation of this manuscript. We also thank B. Shen, C. Bao and Q. Yang for technical support. Y.-K.L. thanks the Caltech SURF programme for financial support. This project was supported by the Defense Advanced Research Projects Agency (DARPA) under the PRIGM:AIMS programme through SPAWAR (grant number N66001-16-1-4046) and the Kavli Nanoscience Institute. Data availability: The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request. Author Contributions: Y.-K.L., Y.-H.L., M.-G.S. and K.V. conceived the idea of EP enhancement in the offset-counter-pumped SBL gyroscope. Y.-K.L., Y.-H.L. and K.V. constructed the theoretical model. M.-G.S. fabricated the ultrahigh-Q silica microresonator and helped Y.-H.L. with the packaging. Y.-H.L. and Y.-K.L. performed the experiment. Z.Y. assisted with the gyroscope sensitivity measurements. All authors analysed the data and wrote the manuscript. The authors declare no competing interests.
Group:Kavli Nanoscience Institute
Funding AgencyGrant Number
Defense Advanced Research Projects Agency (DARPA)UNSPECIFIED
Office of Naval Research (ONR)N66001-16-1-4046
Kavli Nanoscience InstituteUNSPECIFIED
Subject Keywords:Integrated optics; Microresonators; Nonlinear optics; Optical sensors; Photonic devices
Issue or Number:7785
Record Number:CaltechAUTHORS:20190429-082730110
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Official Citation:Lai, Y., Lu, Y., Suh, M. et al. Observation of the exceptional-point-enhanced Sagnac effect. Nature 576, 65–69 (2019) doi:10.1038/s41586-019-1777-z
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:95064
Deposited By: Tony Diaz
Deposited On:29 Apr 2019 15:51
Last Modified:16 Nov 2021 17:09

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