Xiong Han, Ma Xiaodong, Zhang Huaiqing
Opt Express. 2021 Nov 8;29(23):38557-38566. doi: 10.1364/OE.442610.
Heat-sensitive materials have great applications in sensor, detector, and tunable photoelectric devices. However, the wave-thermal effect of the heat-sensitive material is rarely been investigated in the THz range. Here, we propose the incorporation of heat-sensitive material (strontium titanate (STO)) within a THz absorber. The simulated results show that the absorptance and frequency can be dynamically controlled by the temperature of STO. Because the absorbed THz waves are finally converted into heat, then we research the theoretical mechanism of heat generation. Theoretical analysis shows that there are two reasons for the temperature rise: surface plasmon polariton (SPP) and ohmic loss of gold patch; Electromagnetic energy consumption inside the loss materials. To verify the theory, finally, we use COMSOL Multiphysics to research the nanosecond wave-thermal effect. The transient temperature of the wave-thermal effect is calculated quantitatively. The quantitative prediction of temperature variation can provide good guidance for thermal regulation and wave-thermally tunable THz devices.
热敏材料在传感器、探测器和可调谐光电器件中具有广泛应用。然而，热敏材料在太赫兹波段的波热效应鲜有研究。在此，我们提出在太赫兹吸收器中引入热敏材料（钛酸锶（STO））。模拟结果表明，吸收率和频率可由STO的温度动态控制。由于吸收的太赫兹波最终会转化为热量，因此我们研究了发热的理论机制。理论分析表明，温度升高有两个原因：表面等离激元极化激元（SPP）和金贴片的欧姆损耗；损耗材料内部的电磁能量消耗。为验证该理论，最后我们使用COMSOL Multiphysics研究纳秒级波热效应。对波热效应的瞬态温度进行了定量计算。温度变化的定量预测可为热调节和波热可调太赫兹器件提供良好指导。
