基于侧边耦合一维光子晶体微腔的高分辨率光子温度计

High Resolution and Practical Photonic Thermometer by Side-coupled One-dimensional Photonic Crystal Microcavity

针对线上耦合结构的高品质因数一维光子晶体微腔具有极低透射率的缺陷,提出研制一种具有高分辨率、高信噪比、高动态范围的侧边耦合一维光子晶体温度计。通过调制光子晶体单元结构的反射系数以及微腔和耦合波导之间的模场重叠,光子晶体器件的品质因数和透射率得到提高。制备得到的器件品质因数值、灵敏度、消光比和基模与二阶模之间的模式间隔分别为2.7×10^(4)、65.6 pm/℃、0.45和18.5 nm。采用扫频测量技术,该光子温度计具有mK量级分辨率和超过280℃的温度感应范围。

Aiming at in-line coupled one-dimensional photonic crystal(1D PhC)microcavity with high quality factor(Q)but extremely low transmittance,a side-coupled 1D PhC thermometer with high resolution,signal to noise ratio and dynamic range was proposed.Through modulating reflection coefficient of photonic crystal units and overlap of mode field between the microcavity and coupling waveguide,the Q and transmittance of the PhC device were improved.The total Q-factor,sensitivity,extinction ratio,and mode spacing between fundamental and secondary mode of the fabricated PhC device were 2.7×104,65.6 pm/℃,0.45 and 18.5 nm,respectively.By adopting a sweep frequency measurement technique,the resolution of the proposed photonic thermometer reaches millikelvin and the sensing range is over 280℃.