Herein, we present a method for the modification of the refractive index (n), based on employing an organic molecule with a long triplet excited-state lifetime. A host-guest material composed of a cyclic aromatic as the guest and an amorphous steroidal compound as the host was used to modulate n. The guest material exhibited a triplet lifetime longer than 1 s, and a high-density triplet excited-state population was obtained upon excitation with blue-violet light. The refractive index could be changed by 0.002, even when using a relatively low excitation power level of 100 mW cm^-2.

中文翻译：

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低功率下在光激发下积累三重态激子引起的大折射率变化

本文中，我们基于使用具有长三重态激发态寿命的有机分子，提出了一种修改折射率（n）的方法。由环状芳族化合物作为客体和无定形甾族化合物作为主体的主体客体材料被用来调节n。客体材料的三重态寿命超过1 s，并且通过蓝紫色光激发获得了高密度的三重态激发态态。即使使用100 mW cm ^-2的相对较低的激发功率水平，折射率也可以改变0.002 。