一种新型光学传感器的理论和实验研究

Theoretical and experimental study on a new optical sensor

当多孔硅处于有机物蒸汽环境时,由于自身的多孔结构和巨大的比表面积,有机物蒸汽分子将迅速地吸附到多孔硅的表面,并在多孔硅的孔内发生毛细冷凝作用,这将引起多孔硅层有效折射率的变化,从而导致多孔硅微腔反射谱透射峰峰位的变化。本文主要利用Bruggeman介电常数近似理论与光子晶体传输矩阵的方法,建立了多孔硅微腔的理论传感模型。使用光学实验装置对多孔硅微腔进行了传感实验,证明多孔硅微腔可以实现对有机物蒸汽分子种类的检测,且分辨率较高,响应时间和恢复时间短,可重复性好。

Due to capillary condensation of the vapor in the silicon pore when the porous silicon is exposed to vapor of organic species, the average refractive index of Porous Silicon Microcavities （PSMs） is increased. It results in different resonant peak shift in the reflectivity spectra. Sensing model of PSMs is set up by applying the Bruggeman effective medium approximation theory and the method of transfer matrix. Using experimental setup to measure the reflectivity spectrum of PSMs, experimental results prove that it is a feasible optical sensor for organic species detecting. Resolution of the PSMs sensor is high, and response time and resume time is short and has good repeatability.