垂直耦合悬空型氮化硅微盘光学传感器

Vertically Coupled Suspended Silicon Nitride Microdisk Based Optical Sensor

提出了一种垂直耦合型悬空氮化硅微盘谐振型传感器,该传感器由一个底部非悬空的接入波导和一个顶部悬空的微盘腔组成,并用实验证明了其具有较高的器件灵敏度和良好的机械稳定性。对于半径40μm的微盘,在1548.98nm谐振波长下可以实现超过104的品质因数以及大小适中、5.66nm的自由光谱范围。该传感器的灵敏度可通过覆盖不同的有机液体来测量,实验测得值约为554nm/RIU。该三维传感器的制备与传统的光刻工艺相兼容,利于大批量低成本生产,同时凭借器件尺寸小、工艺简单、检测灵敏度高、响应快、免标记等特点,在国防安全、生物检测和环境监测等方面具有广阔的应用前景。

A vertically coupled suspended silicon nitride resonator sensor is experimentally demonstrated,which consists of a bottom-layer un-suspended access waveguide and a top-layer suspended micro-disk cavity.The presented sensor can realize a high device sensitivity with a good mechanical stability.For a 40 μm-radius disk,a quality factor of over 10 4 and a moderate free-spectral range of 5.66 nm can be obtained at a resonant wavelength of 1548.98 nm.The sensitivity of the sensor can be measured by covering different organic liquids,and the experimental value is about 554 nm/RIU.The fabrication of the proposed three-dimensional sensor is compatible with the conventional photolithography process,which would benefit its mass production at low cost.At the same time,due to its characteristics of small size,simple process,high sensitivity,fast response and mark-free,the sensor has broad application prospects in national defense safety,biological dection and environment monitoring and other aspects.