【作者】 曹昌胜；

【导师】 罗斌；

【作者基本信息】 西南交通大学 ， 通信与信息系统， 2005， 硕士

【摘要】 薄膜干涉滤光片具有通带窄、插入损耗低,温度稳定性好等特点,因此,采用薄膜干涉滤光片作为滤波器的调谐器件得到了广泛的研究。 本文基于薄膜干涉滤光片角度调谐的基本原理,首次提出并实现了一种线性调谐光滤波器。其原理是设计一个包括步进电机等在内的机构装置,使得滤光片的峰值波长与步进电机的旋转角之间有良好的线性关系。这为光滤波器的峰值波长定位带来很大的方便,直接通过步进电机步数就可以来确定滤波器的峰值波长。 在理论方面,以一个三腔结构的薄膜干涉滤光片为研究对象,通过多层介质薄膜的膜系特征矩阵,得到了滤光片的峰值波长与调谐角度之间的依赖关系;在此基础上,结合机构装置的结构参量,进而分析了不同的机构装置参量对线性调谐光滤波器的线性度的影响。 在实验方面,选用一个成品窄带滤光片,设计步进电机控制电路,实现了一个线性调谐光滤波器装置。利用1550nm波段的LED作为宽带光源,通过测量经过线性调谐光滤波器后的光谱曲线,对滤波器的线性调谐特性进行了测试,对机构装置的参量进行优化后,在1548nm～1560nm波长调谐范围内,取得了线性度在±0.4nm内的实验结果。更多还原

【Abstract】 Tunable optical filters based on thin-film interference filters are extensively researched due to the good characteristics of thin-film interference filters such as narrow bandwidth, low insertion loss and fine temperature stability.In this paper, a new linear tuning filter based on the angle-tuned thin-film interference filter is design for the first time. The idea of the linear tuning filter is to design a mechanism including a stepping motor to make the central wavelength of the filter and rotary angle of stepping motor become linearity. So it is very convenient to measure central wavelength of the filter. It can determine the central wavelength of the linear tuning filter directly through step count of stepping motor.Theoretically, through transfer matrix method of multilayer thin-film interference filter and parameters of the mechanism, the relationship between central wavelength of the filter and rotary angle of stepping motor is calculated with a three-cavity thin-film interference filter. Then, the influence on linearity of the linear tuning filters is analyzed with different parameters of the mechanism.Experimentally, a linear tuning filter’s set including a finished product narrowband thin-film interference filter and control circuit of stepping motor has been designed. Then, making use of LED in 1550nm as broadband light source, the spectrum curve is achieved after light through the linear tuning filter. Linearity of the tuning filter is analyzed through the spectrum curve. In the end, the experimental results show that the linearity of the linear tuning filter is less than ± 0.4nm with a tuning range of 1548nm~1560nm by means of optimizing parameters of the mechanism.更多还原