Negative-index metamaterials are significantly limited by their inherent losses. We demonstrate that a negative index without dissipative and reflective losses can be achieved in subwavelength dielectric cuboid arrays. We can avoid reflection by making dielectric cuboids exhibit the resonant forward scattering of light, while dissipative loss is inherently absent in dielectric materials. A joint study combining theoretical and experimental research demonstrates that loss-free negative-index metamaterials can be realized. They fulfill the criteria of negative refraction based on causality, while conventional active loss compensation schemes lead to the disappearance of negative refraction by causality.

中文翻译：

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在介电元原子中使用前向光散射的无损负折射率超材料

负折射率超材料受到其固有损耗的明显限制。我们证明，在亚波长电介质长方体阵列中可以实现没有耗散和反射损耗的负折射率。我们可以通过使电介质长方体表现出共振的光正向散射来避免反射，而电介质材料本来就不存在耗散损耗。理论研究与实验研究相结合的联合研究表明，可以实现无损耗的负折射率超材料。它们满足基于因果关系的负折射标准，而常规的主动损耗补偿方案会导致因果关系导致的负折射消失。