Diaphragm Type Ultra Miniature Optical Fiber Pressure Sensor with Sleeve

(1)在硅衬底上形成的凹槽中形成多晶硅间隔片，使纤维与膜片之间的间隙保持在几μ m，并通过CMP（化学机械抛光）在间隔片之外抛光。这种方法可以使膜片表面呈镜像状态。CCP（电容耦合等离子体）蚀刻是为了形成具有垂直壁的套筒。(2)开发了将膜片安装在光纤端侧的方法。具体方法是将带半反射镜的125 μm多模光纤置于垂直微动机械系统上，插入显微镜下的膜片套筒内。在接下来的步骤中，套筒由玻璃微毛细管提供的紫色粘附树脂固定。(3) 1.3 μm激光通过1 × 2光耦合器注入光纤，膜片反射的光输入光探测器。膜片的传感器施加的压力从0到150mmhg表示由光学干涉引起的正弦响应。实验结果表明，所制备的压力传感器能够满足医用血压测量的要求。

(1) Polycrystalline silicon spacer which keeps the gap between a fiber and a diaphragm at few um is formed in the grave formed on the silicon substrate and polished out besides the spacer by CMP (Chemical Mechanical Polishing). This method can make the diaphragm surface be a mirror state. CCP (Capacitive Coupling Plasma) etching is used in order to form the sleeve with a vertical wall.(2) The method of mounting the diaphragm on the end side of the optical fiber has been developed. The concrete way is that the 125 μm multi mode optical fiber with an half mirror is set on the vertical micro moving mechanical system and inserted in the sleeve of the diaphragm under the microscope. In the next step, the sleeve is fixed by the violet adhesion resin which is supplied by the glass micro capillary.(3) 1.3 μm laser light through the 1 x 2 photo coupler is injected into the fiber and the reflected light from the diaphragm is inputted into the photo detector. The sensor of the diaphragm applied the pressure from 0 to 150 mmHg represented a sinusoidal response caused by optical interference. From this result, it is proved that the fabricated pressure sensor satisfies the performance to measure blood pressure for medical applications.