基于集成谐振及干涉效应的温度自补偿薄膜厚度检测方法

The film thickness detection with temperature self-compensating based on integrated resonance and interference effects

塑料薄膜厚度检测结果受环境温度影响较大。基于微纳光纤环形谐振腔(MLR)和法布里—珀罗(F-P)干涉仪,提出一种集成薄膜厚度检测温度自补偿方法,先利用聚二甲基硅氧烷(PDMS)封装的MLR监测温度变化,再利用薄膜前后表面形成的F-P腔测量薄膜厚度,最后根据反射光谱表现的MLR和F-P干涉的集成效应,实现单光源单解调装置的温度和薄膜厚度同时解调,达到薄膜厚度测量的温度自补偿效果。结果表明:集成薄膜厚度检测温度自补偿方法能够准确检测由温度波动引起的薄膜厚度变化,温度灵敏度为166 pm/℃,温度为25~55℃时可实现温度自补偿,最大相对误差由0.51%降低至0.11%。与其他厚度检测方法相比,集成于检测厚度传感器的温度自补偿薄膜厚度检测方法灵敏度高、实现无损检测、快速检测及测量不受温度影响,在石油化工及生物检测领域提高薄膜测厚效率、提升测厚准确度方面具有较好应用。

To address the issue of plastic film thickness measurement being significantly affected by ambient temperature,we proposed a self-compensation method that involved measuring the temperature of the film.This method combines a microfiber loop resonator(MLR)and a Fabry-Perot(F-P)interferometer.The MLR,coated with polydimethylsiloxane(PDMS),is used to monitor temperature changes,while the F-P cavity formed on the front and back surfaces of the film is used to measure the thickness.By considering the combined effect of MLR and F-P interference in the reflection spectrum,we can simultaneously demodulate the temperature and film thickness using a single light source and demodulation device.This achieves temperature self-compensation for film thickness measurement.The experimental results demonstrate that our sensor method can accurately detect changes in film thickness caused by temperature fluctuations.The temperature sensitivity is 166 pm/℃,and successful temperature self-compensation is achieved within the temperature range of 2555℃.After temperature compensation,the maximum relative error is reduced from 0.51%to 0.11%.In comparison with other thickness measurement methods,our technology offers a solution that integrates temperature compensation into the thickness measurement sensor.It provides numerous advantages,including high sensitivity,non-destructive testing,rapid detection,and measurement unaffected by temperature.Therefore,it has great potential for applications in the petrochemical and biological detection fields,as it can enhance the efficiency and accuracy of thickness measurement for thin films.