1. Optical Limiter Based on PT-Symmetry Breaking of Reflectionless Modes
- Author
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Riboli, F., Kononchuk, R., Tommasi, F., Boschetti, A., Suwunnarat, S., Anisimov, I., Vitebskiy, I., Wiersma, D. S., Cavalieri, S., Kottos, T., and Chabanov, A. A.
- Subjects
Physics - Optics - Abstract
The application of parity-time (PT) symmetry in optics, especially PT-symmetry breaking, has attracted considerable attention as a novel approach to controlling light propagation. Here, we report optical limiting by two coupled optical cavities with a PT-symmetric spectrum of reflectionless modes. The optical limiting is related to broken PT symmetry due to light-induced changes in one of the cavities. Our experimental implementation is a three-mirror resonator of alternating layers of ZnS and cryolite with a PT-symmetric spectral degeneracy of two reflectionless modes. The optical limiting is demonstrated by measurements of single 532-nm 6-ns laser pulses. At fluences below 10 mJ/cm2, the multilayer exhibits a flat-top passband at 532 nm. At higher fluences, laser heating combined with the thermo-optic effect in ZnS leads to cavity detuning and PT-symmetry breaking of the reflectionless modes. As a result, the entire multilayer structure quickly becomes highly reflective, protecting itself from laser-induced damage. The cavity detuning mechanism can differ at much higher limiting thresholds and include nonlinearity., Comment: 17 pages, 5 figures
- Published
- 2023
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