基于光在熔锥光纤中传输的基本原理,分析了在外界温度不断变化的情况下涂覆折射率匹配液的熔锥光纤传输损耗特性。利用计算机仿真与实验得到了这种器件的传输损耗特性曲线,计算机仿真结果和实验结果的一致性很好地说明了熔锥光纤传输特性随温度变化的关系。随着外界环境温度的升高,折射率匹配液的折射率降低,熔锥光纤所携带的光功率占总光功率的比值增加,导致传输损耗减小。同时利用这种传输特性得到了一种温度可调的短通滤波器件,在一定温度下,这种滤波器对长波的滤波大于35dB,其滤波截止波长随温度升高而向长波方向漂移,温度系数是40nm/℃。
Based on the basic principles of tapered optic fiber transmission,this paper primarily analyzes the transmission characteristics of fused tapered optic fiber which is coated with refractive index-matching fluid versus the index-matching liquids′ temperature variations.The transmission loss curves of computer simulation and experiment are very close in tendency.The results show the relationship between the transmission characteristics of tapered optic fiber and the temperature changes.With the temperature increment of outside ambient,the refractive index of index-matching liquids declines.Based on this,the ratio of the optical power carried by the tapered fiber to the total optical power increases.As a result,transmission loss is reduced.Based on the transmission characteristics of this optical device,a temperature-controlled short-pass filter is proposed,the cut-off wavelength of this filter becomes longer with the temperature increased.The rejection efficiency can be above 35 dB and the temperature coefficient of this filter is 40 nm/℃.