为了实时监测光学薄膜的厚度,设计和制作了一款照明和采集干涉图谱为一体的石英光纤柬探头,基于光学多道分析器、白色LED光源和计算机等设备组成,实现高精度监测薄膜厚度的测量系统。以薄膜等厚干涉原理为依据,分析了干涉相消波长测量薄膜厚度的原理与可行性。用汞灯标准谱线对光学多道分析器进行定标,通过自制的石英光纤束探头照明和采集干涉图谱,经光学多道分析器与计算机处理获得薄膜反射干涉相消光波长,计算得到光学薄膜厚度。测量系统通过对手机屏幕贴膜和不干胶薄膜样品的涂层厚度测试,可以监测纳米量级的薄膜厚度.
In order to realize the real-time monitoring of optical thin film thickness, a high precision monitoring system composed of a 2-in-1 silica fiber bundle probe, an optical multichannel analyzer (OMA) and a polychromatic LED was designed. Based on thin film interference principle of equal thickness, the feasibility of thin film thickness measurement related to destructive interference wavelengths was analyzed. With mercury standard spectral lines, acquireing the interference pattern via fiber bundle probe, after OMA and PC procession, the destructive interference wavelengths from thin film reflection can be obtained. The system was tested with the film coating of cellphone screen and the adhesive sticker coating samples, the minimum thickness which can be measured is several nanometers.