Birefringence is a fundamental optical property that can induce phase retardation of polarized light. Tuning the birefringence of liquid crystals is a core technology for light manipulation in current applications in the visible and infrared spectral regions. Due to the strong absorption or instability of conventional liquid crystals in deep-ultraviolet light, tunable birefringence remains elusive in this region, notwithstanding its significance in diverse applications. Here we show a stable and birefringence-tunable deep-ultraviolet modulator based on two-dimensional hexagonal boron nitride. It has an extremely large optical anisotropy factor of 6.5 × 10−12 C2 J−1 m−1 that gives rise to a specific magneto-optical Cotton–Mouton coefficient of 8.0 × 106 T−2 m−1, which is about five orders of magnitude higher than other potential deep-ultraviolet-transparent media. The large coefficient, high stability (retention rate of 99.7% after 270 cycles) and wide bandgap of boron nitride collectively enable the fabrication of stable deep-ultraviolet modulators with magnetically tunable birefringence.
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The data that support the findings of this study are available within the paper and the Supplementary Information. Other relevant data are available from the corresponding authors on reasonable request. Source data are provided with this paper.
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We acknowledge support by the National Natural Science Foundation of China (No. 51920105002, 52125309, 52188101, 51991343 and 51991340), the Guangdong Innovative and Entrepreneurial Research Team Program (No. 2017ZT07C341), the Shenzhen Basic Research Project (No. WDZC20200819095319002 and JCYJ20190809180605522), the National Key R&D Program (2018YFA0307300) and the Bureau of Industry and Information Technology of Shenzhen for the ‘2017 Graphene Manufacturing Innovation Centre Project’ (No. 201901171523). We thank L. Qiu, J. Liu, Y. Hao, J. Tan, M. Liu, S. Lan, F. Cai, L. Dai, Z. Xie and N. Lei for discussions, sample fabrication and part of material characterization.
The authors declare no competing interests.
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Xu, H., Ding, B., Xu, Y. et al. Magnetically tunable and stable deep-ultraviolet birefringent optics using two-dimensional hexagonal boron nitride. Nat. Nanotechnol. 17, 1091–1096 (2022). https://doi.org/10.1038/s41565-022-01186-1