A novel strategy to broadband nanoimaging of microworld in the near field is reported by using a folded-geometry transformation. This approach relies exclusively on hyperbolic metamaterials with engineered anomalous hyperbolic dispersion. The restriction on the signs of gradient in the dispersion enables invariable propagation angle of hyperbolic polaritons at different wavelengths, which could be utilized to dramatically broaden the bandwidth. Interestingly, a pseudo-broadband nanoimaging based on hyperbolic metamaterial consisting of alternating metal (e.g. Ag) and plasmonic nanocomposite (e.g. Au-Al₂O₃) layers is demonstrated. Such strategy of transformation optics-based broadband nanoimaging allows for a new class of robustly manufacturable nanophotonic systems, although additional gain-assisted compensation is needed to improve the performance of nanoimaging.

通过使用折叠几何变换，报道了一种在近距离对微世界进行宽带纳米成像的新策略。该方法仅依赖于具有工程异常双曲线弥散的双曲线超材料。对色散中梯度符号的限制使得双曲极化子在不同波长下的传播角度不变，这可以用来显着拓宽带宽。有趣的是，基于双曲线超材料的伪宽带纳米成像由双金属（例如Ag）和等离子体纳米复合材料（例如Au-Al ₂ O _3）组成）层进行了演示。尽管需要额外的增益辅助补偿来改善纳米成像的性能，但是这种基于光学转换的宽带纳米成像的策略允许一类新型的可制造的纳米光子系统。