为满足加速度传感器微型化、低成本的需求，提出了一种带有单微环谐振腔的悬臂梁式光学加速度传感器结构，采用耦合模和传输矩阵理论求取了微环谐振器的传递函数，利用检测同一波长处光强度变化的新测量方法实现了对加速度的探测，从而得到了加速度传感器的灵敏度和探测极限，深入研究了不同结构参数对系统灵敏度的影响，数值仿真并分析了输出端口的光谱特性。结果表明：加速度传感器在外界加速度作用时，悬臂梁在应力的作用下会发生弯曲，使得固定在悬臂梁上的微环谐振器发生形变，即微环谐振器的长度和折射率都发生了变化，从而光在微环谐振器中的传输特性发生变化，因此可以通过探测微环输出端光场强度的变化来测定加速度值；悬臂梁的长度、厚度以及微环谐振腔的固定位置都是影响加速度传感器性能的直接因素，并且选择最佳的结构参数可以有效地提高系统灵敏度和精度。经过数值仿真，对于信噪比为30 dB系统，波长在1.515μm处，悬臂梁的长度、厚度分别为180和3μm时，系统的灵敏度可达到2.112 g -1，探测极限为1.421×10-3 g ，因此在悬臂梁可承受的范围内，选取长度较长的悬臂梁结构能够有效地改善系统的灵敏度和探测极限。该结构为制备高灵敏度、低成本、易于加工的加速度传感器及可嵌入式微型光学器件提供理论基础。%A structure of an optical accelerometer based on an optical single ring resonator located onto the cantilever is proposed to meet the requirements of microminiaturization and economical applications in the present paper .The spectra of out port are obtained using transfer matrix method and theory of coupled modes .According to the measurement of intensity of drop port at the same wavelength ,the influences of different structure parameters on the sensitivity of the whole acceleration sensor are ana-lyzed .The results show that the cantilever length and thickness and the ring resonator position are all key factors which can in-fluence the sensing property of acceleration sensor .Hence the sensitivity can be effectively improved by adjusting the factors mentioned above .The sensitivity reaches up to 2.112 g -1 and the limit of detection can achieve 1.421 × 10-3 at 1.515μm with a cantilever of 180 μm in length and 3 in thickness for a 30 dB signal-noise system .Such structure has great potential to develop low-cost and easy made high sensitive acceleration meter .
展开▼
