Coherent control of (non-)Hermitian mode coupling: tunable chirality and exceptional point dynamics in photonic microresonators

Bülent Aslan; Riccardo Franchi; Stefano Biasi; Salamat Ali; Davide Olivieri; Lorenzo Pavesi

doi:10.1038/s41377-025-02176-3

Your Location：

Home >

Browse articles >

Coherent control of (non-)Hermitian mode coupling: tunable chirality and exceptional point dynamics in photonic microresonators

Original Articles

- Coherent control of (non-)Hermitian mode coupling: tunable chirality and exceptional point dynamics in photonic microresonators
- Coherent control of (non-)Hermitian mode coupling: tunable chirality and exceptional point dynamics in photonic microresonators
- Light: Science & Applications 2026年15卷第5期页码：1665-1678
- Affiliations：
  
  1.Nanoscience Laboratory, Department of Physics, University of Trento, Povo, Italy
  2.Present address: Nanomaterials & Nanostructure Optics, Department of Electrical and Computer Engineering, Boston University, Boston, MA, USA
- Author bio：
  
  Stefano Biasi (stefano.biasi@unitn.it)
- Funds：
- DOI：10.1038/s41377-025-02176-3
  中图分类号：
- 收稿：2025-04-10，
  
  修回：2025-12-18，
  
  录用：2025-12-21，
  
  网络首发：2026-03-06，
  
  纸质出版：2026-05-31
- Accepted：
Scan QR Code
Bülent Aslan, Riccardo Franchi, Stefano Biasi, 等. Coherent control of (non-)Hermitian mode coupling: tunable chirality and exceptional point dynamics in photonic microresonators[J]. Light: Science & Applications, 2026,15(5):1665-1678.

Aslan, B. et al. Coherent control of (non-)Hermitian mode coupling: tunable chirality and exceptional point dynamics in photonic microresonators. Light: Science & Applications, 15, 1665-1678 (2026).
Bülent Aslan, Riccardo Franchi, Stefano Biasi, 等. Coherent control of (non-)Hermitian mode coupling: tunable chirality and exceptional point dynamics in photonic microresonators[J]. Light: Science & Applications, 2026,15(5):1665-1678. DOI： 10.1038/s41377-025-02176-3.

Aslan, B. et al. Coherent control of (non-)Hermitian mode coupling: tunable chirality and exceptional point dynamics in photonic microresonators. Light: Science & Applications, 15, 1665-1678 (2026). DOI： 10.1038/s41377-025-02176-3.

摘要

Abstract

This work introduces a novel on-chip integrated photonic device

the Dynamically Reconfigurable Unified Microresonator (DRUM)

enabling full and dynamic control of Hermitian and non-Hermitian modal coupling between counter-propagating modes in a microresonator. The DRUM consists of a microresonator coupled to two tunable side waveguides

each incorporating a Mach-Zehnder Interferometer and a phase shifter

allowing for independent manipulation of the amplitude and phase of the coupling coefficients. This unique architecture facilitates a continuous and arbitrary transition between diabolic points (DPs) and exceptional points (EPs). We experimentally demonstrate the versatility of the DRUM through several key functionalities: dynamic tuning of the resonance spectral lineshape

coherent suppression of backscattering to achieve an ideal DP

and operation in both Hermitian and non-Hermitian states

enabling continuous chirality tuning and dynamic steering between two EPs. The device achieves a chirality of ±1 at the EPs

indicating strong directionality in light propagation. The experimental results

supported by a theoretical model based on Temporal Coupled Mode Theory

pave the way for reconfigurable photonic devices that exploit (non-)Hermitian dynamics for advanced functionalities

with potential applications ranging from high-sensitivity sensors to neuromorphic computing. The DRUM overcomes the limitations of previous implementations by offering unprecedented control over the coupling between counter-propagating modes within a single integrated device.

关键词

Keywords

references

Ashida, Y., Gong, Z. P. & Ueda, M. Non-Hermitian physics. Adv. Phys. 69 , 249–435 (2020)..

Feng, L., El-Ganainy, R. & Ge, L. Non-Hermitian photonics based on parity–time symmetry. Nat. Photonics 11 , 752–762 (2017)..

Özdemir, ŞK. et al. Parity-time symmetry and exceptional points in photonics. Nat. Mater. 18 , 783–798 (2019)..

Wang, C. Q. et al. Non-Hermitian optics and photonics: from classical to quantum. Adv. Opt. Photonics 15 , 442–523 (2023)..

Feng, L. et al. Demonstration of a large-scale optical exceptional point structure. Opt. Express 22 , 1760–1767 (2014)..

Calabrese, A. et al. Unidirectional reflection from an integrated “Taiji” microresonator. Photonics Res. 8 , 1333–1341 (2020)..

Lin, Z. et al. Unidirectional invisibility induced by PT -symmetric periodic structures. Phys. Rev. Lett. 106 , 213901 (2011)..

Hodaei, H. et al. Parity-time-symmetric microring lasers. Science 346 , 975–978 (2014)..

Wang, C. Q. et al. Coherent perfect absorption at an exceptional point. Science 373 , 1261–1265 (2021)..

Hörner, H. et al. Coherent perfect absorption of arbitrary wavefronts at an exceptional point. Phys. Rev. Lett. 133 , 173801 (2024)..

Soleymani, S. et al. Chiral and degenerate perfect absorption on exceptional surfaces. Nat. Commun. 13 , 599 (2022)..

Peng, B. et al. Chiral modes and directional lasing at exceptional points. Proc. Natl. Acad. Sci. USA 113 , 6845–6850 (2016)..

Chen, Y. H. et al. Electrically reconfigurable mode chirality in integrated microring resonators. Laser Photonics Rev. 18 , 2301289 (2024)..

Qie, J. R., Wang, C. Q. & Yang, L. Chirality induced nonreciprocity in a nonlinear optical microresonator. Laser Photonics Rev. 17 , 2200717 (2023)..

Muñoz de las Heras, A. et al. Nonlinearity-induced reciprocity breaking in a single nonmagnetic Taiji resonator. Phys. Rev. Appl. 15 , 054044 (2021)..

Zhong, Q. et al. Sensing with exceptional surfaces in order to combine sensitivity with robustness. Phys. Rev. Lett. 122 , 153902 (2019)..

Mao, W. B. et al. Exceptional-point-enhanced phase sensing. Sci. Adv. 10 , eadl5037 (2024)..

Guo, A. et al. Observation of PT -symmetry breaking in complex optical potentials. Phys. Rev. Lett. 103 , 093902 (2009)..

Qin, G. Q. et al. Experimental realization of sensitivity enhancement and suppression with exceptional surfaces. Laser Photonics Rev. 15 , 2000569 (2021)..

Wang, C. Q. et al. Electromagnetically induced transparency at a chiral exc eptional point. Nat. Phys. 16 , 334–340 (2020)..

Lee, H. et al. Chiral exceptional point enhanced active tuning and nonreciprocity in micro-resonators. Light Sci. Appl. 14 , 45 (2025)..

Lee, H. et al. Chiral exceptional point and coherent suppression of backscattering in silicon microring with low loss Mie scatterer. eLight 3 , 20 (2023)..

Franchi, R. et al. The infinity-loop microresonator : a new integrated photonic structure working on an exceptional surface. APL Photonics 8 , 056111 (2023)..

Li, J. W. et al. On-chip fabrication-tolerant exceptional points based on dual-scatterer engineering. Nano Lett. 24 , 3906–3913 (2024)..

On, M. B. et al. Programmable integrated photonics for topological Hamiltonians. Nat. Commun. 15 , 629 (2024)..

Dai, T. X. et al. A programmable topological photonic chip. Nat. Mater. 23 , 928–936 (2024)..

Reprogrammable photonic microchips. https://ipronics.com https://ipronics.com .

Biasi, S. et al. The Taiji microresonator as an unidirectional spiking neuron. Preprint at https://doi.org/10.48550/arXiv.2410.03257 https://doi.org/10.48550/arXiv.2410.03257 (2024).

Jacques, M. et al. Optimization of thermo-optic phase-shifter design and mitigation of thermal crosstalk on the SOI platform. Opt. Express 27 , 10456–10471 (2019)..

Vivien, L. & Pavesi, L. Handbook of Silicon Photonics (Boca Raton, CRC Press, 2013).

Biasi, S. et al. Interferometric method to estimate the eigenvalues of a non-Hermitian two-level optical system. Photonics Res. 10 , 1134–1145 (2022)..

Bandres, M. A. et al. Topological insulator laser: experiments. Science 359 , eaar4005 (2018)..

Fan, H. B., Fan, H. W. & Fan, H. L. Multiple Fano resonance refractive index sensor based on a plasmonic metal-insulator-metal based Taiji resonator. J. Opt. Soc. Am. B 39 , 32–39 (2022)..

Hayenga, W. E. et al. Direct generation of tunable orbital angular momentum beams in microring lasers with broadband exceptional points. ACS Photonics 6 , 1895–1901 (2019)..

Muñoz de las Heras, A. & Carusotto, I. Unidirectional lasing in nonlinear Taiji microring resonators. Phys. Rev. A 104 , 043501 (2021)..

Franchi, R. The Taiji and Infinity-Loop Microresonators: Examples of Non-Hermitian Photonic Systems . PhD thesis, Università degli Studi di Trento, Trento (2023).

Aslan, B. et al. On the spectral response of a Taiji-CROW device. Opt. Express 32 , 15177–15198 (2024)..

Zeng, S. W. et al. Unidirectional hybrid diode laser through the integration of a hook-shaped traveling-wave semiconductor optical amplifier and Taiji ring resonator. Opt. Lett. 48 , 1132–1135 (2023)..

Parto, M. et al. Non-Hermitian and topological photonics: optics at an exceptional point. Nanophotonics 10 , 403–423 (2021)..

Biasi, S. et al. Hermitian and non-Hermitian mode coupling in a microdisk resonator due to stochastic surface roughness scattering. IEEE Photonics J. 11 , 6101114 (2019)..

Doppler, J. et al. Dynamically encircling an exceptional point for asymmetric mode switching. Nature 537 , 76–79 (2016)..

Li, A. et al. Backscattering in silicon microring resonators: a quantitative analysis. Laser Photonics Rev. 10 , 420–431 (2016)..

Li, A. & Bogaerts, W. Using backscattering and backcoupling in silicon ring resonators as a new degree of design freedom. Laser Photonics Rev. 13 , 1800244 (2019)..

Biasi, S., Franchi, R. & Pavesi, L. Interferometric cavity ringdown technique for ultrahigh Q-factor microresonators. Opt. Lett. 47 , 4083–4086 (2022)..

Franchi, R. et al. On the response of the Taiji microresonator against small perturbation of the counter propagating mode. In Proc. SPIE 12004, Integrated Optics: Devices, Materials, and Technologies XXVI 1200406 (ed. Sonia M. et al.) (San Francisco, CA, USA, SPIE, 2022).

Heebner, J., Grover, R. & Ibrahim, T. Optical Microresonators: Theory, Fabrication, and Applications (New York, Springer, 2008).

McCutcheon, W. Backscattering in nonlinear microring resonators via a Gaussian treatment of coupled cavity modes. APL Photonics 6 , 066103 (2021)..

Morichetti, F. et al. Roughness induced backscattering in optical silicon waveguides. Phys. Rev. Lett. 104 , 033902 (2010)..

Bazzanella, D. et al. PRECISE photonic hybrid electromagnetic solver. IEEE Photonics J. 14 , 3026310 (2022)..

浏览量

Downloads

CSCD

文章被引用时，请邮件提醒。

Submit

工具集

关联资源

Robust chirality through merging BICs

Quantum-enhanced reconfigurable in-memory stochastic computing

Dual-comb absolute ranging reaches orbit

Organic small-molecule NIR-Ⅱ fluorophores for tumor phototheranostics

Phonon-polaritonic skyrmions: transition from bubble- to Néel-type