全光纤微型珐-珀干涉式高温传感器

All-fiber miniature Fabry-Perot interferometer as high temperature sensor

通过在单模光纤SMF28e后有轴心偏移地熔接一段特种光子晶体光纤(MM-HNA-5)制作了一种全光纤微型珐-珀(F-P)干涉仪。分析了这种干涉仪的光学原理和形成机理,并利用MM-HNA-5光纤热光系数较大的特点,将这种干涉仪应用于温度测量。实验结果表明:这种干涉传感器可测量的高温范围可达1200℃,远大于常规传感器的测量范围,且当干涉腔长为3.46mm时,其光程差的温度灵敏度约为103nm/℃,线性度为0.9957。可以预见:这种结构稳定、体积小、精度高、测温范围广的全光纤F-P干涉温度传感器在国防及民用工业中将具有极大的潜在应用价值。

All-fiber miniature Fabry-Perot（F-P） interferometer was fabricated by splicing one section of special photonic crystal fiber（MM-HNA-5） to a single-mode fiber SMF28e with an axis offset.The optical principle and mechanism of the miniature F-P interferometer was analyzed.The MM-HNA-5 fiber had much larger thermo-optical coefficient,thus could be used for temperature measurement.Experimental results show that the temperature measurement range of the proposed sensor is larger than that of the conventional ones,and it is up to 1 200 ℃ .In particular,when the length of the F-P cavity was about 3.46 mm,the temperature sensitivity of the optical path difference was 103 nm/℃,and the linearity of temperature measurement was 0.995 7.This kind of F-P temperature sensor will have potential applications to national defense and civil industry due to its stable structure,small size,high sensitivity and large measurement range.