Temperature-adjustable optical properties of two types of one-dimensional photonic superlattices made from lithium niobate or liquid crystal are theoretically investigated. The control of band structures and density of states is achieved through the temperature with various values of refractive index, layer width, and propagation wavelength. It is presented that a null photonic gap appears at certain temperature points, which are decided by the ratio of layer width and the refractive index. It is shown that the spatial average of the wave vector $\langle k\rangle $ vanishes at a specific temperature as functions of the layer thickness and refractive index. The values of the temperature corresponding to zero-refractive-index (zero-${\langle n \rangle}$) are demonstrated to be suppressed when the refractive index or the ratio of the layer width is enhanced. Null photonic gap and zero-${\langle n \rangle}$ can appear simultaneously at certain wavelengths in the range of visible light, which can be modulated by the temperature. This implies the importance of one-dimensional photonic superlattices made from temperature-controllable-refractive-index materials for many important practical applications.

中文翻译：

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用温度可控折射率材料控制光子超晶格中的零光子隙和零折射率

从理论上研究了两种由铌酸锂或液晶制成的一维光子超晶格的温度可调光学特性。通过具有各种折射率，层宽度和传播波长的温度来实现对带结构和状态密度的控制。结果表明，在某些温度点出现空的光子间隙，这取决于层宽与折射率之比。可以看出，在特定温度下，波矢量$ \ langle k \ rangle $的空间平均值随层厚度和折射率的变化而消失。对应于零折射率的温度值（零- $ {\ langle n \ rangle} $当提高折射率或层宽的比率时，证实了α）被抑制。在可见光范围内的某些波长下，空光子间隙和零- $ {\ langle n \ rangle} $可以同时出现，这可以通过温度进行调制。这暗示了由温度可控的折射率材料制成的一维光子超晶格对于许多重要的实际应用的重要性。