【摘要】 为提高光学薄膜的监控精度和薄膜产品成品率,分别采用经典和现代滤波技术设计了相应的数字滤波器,对薄膜光学监控信号进行了处理,对光学监控信号极值点附近的信号进行了分析。理论模拟的结果表明,经典滤波器和现代滤波器对薄膜监控信号的噪声均有较大的滤出作用,但均造成了信号的延迟。进一步用可编程序控制器和组态软件建立了一套监控系统,将两种滤波器串联使用,在可接受的信号延迟时间下,镀制了单腔滤光片,在实验中将光学监控信号的均方根信噪比提高了6DB以上,验证了数字滤波器的作用。更多还原

【Abstract】 To improve the optical coating monitor accuracy, both classical and modern digital filters are designed. The optical monitor signal from thin film deposition are processed by above digital filters. Theoretical analysis showed that the noise was decreased by digital filters. A monitor system was then established via PLC and optical monitor system manufactured by Nanguang Inc. Experiments showed the S/N ratio was improved more than 6DB by applying digital signal processing method.更多还原