Parity–time-symmetric whispering-gallery microcavities

By Bo Peng, Ş. Özdemir, F. Lei, Faraz Monifi, M. Gianfreda, Guilu Long, Shanhui Fan, Franco Nori, C. Bender, Lan Yang. Nature Physics, 2013

2,235 citations recorded by the source corpus.

Optical systems combining balanced loss and gain provide a unique platform to implement classical analogues of quantum systems described by non-Hermitian parity–time (PT)-symmetric Hamiltonians. Such systems can be used to create synthetic materials with properties that cannot be attained in materials having only loss or only gain. Here we report PT-symmetry breaking in coupled optical resonators. We observed non-reciprocity in the PT-symmetry-breaking phase due to strong field localization, which significantly enhances nonlinearity. In the linear regime, light transmission is reciprocal regardless of whether the symmetry is broken or unbroken. We show that in one direction there is a complete absence of resonance peaks whereas in the other direction the transmission is resonantly enhanced, a feature directly associated with the use of resonant structures. Our results could lead to a new generation of synthetic optical systems enabling on-chip manipulation and control of light propagation. It is now shown that coupled optical microcavities bear all the hallmarks of parity–time symmetry; that is, the system’s dynamics are unchanged by both time-reversal and mirror transformations. The resonant nature of microcavities results in unusual effects not seen in previous photonic analogues of parity–time-symmetric systems: for example, light travelling in one direction is resonantly enhanced but there are no resonance peaks going the other way.

Subfields: Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/29cddeaab1f69cfa7feb83a8e54d79dd4df5f77a

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In Atomic and Molecular Physics, and Optics

Citations in the corpus

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Symmetry and Topology in Non-Hermitian Physics (2018, background): “Examples include power oscillations [40,74], unidirectional invisibility [48,74,75,77], high-performance lasers [46,47,51,59,78–80,84], exceptional-point encirclement [82,86,87,95], and enhanced sensitivity [50,58,67, 90,91].”
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Magnetless Microwave Circulators Based on Spatiotemporally Modulated Rings of Coupled Resonators (2016, background): “Nonlinearity was also studied as a potential path to magnetless nonreciprocity, especially at optical frequencies [17]–[20].”
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