We report a compact and robust micro air cavity (MAC) incorporated tip tapered photonic crystal fiber (PCF) based interferometer point probe for refractive index (RI) sensing. Two sections of PCF are spliced and tapered and the tapered collapsed section is cleaved to form a tip tapered PCF. One end of the PCF is spliced with a single mode fiber while the tapered tip of PCF is subjected to laser micromachining which results in the formation of a micro-groove at the tip. The laser micromachining enables the formation of micro-groove even on a roughly cleaved tapered section. The micro-groove is post processed using a fusion splicer in order to form a MAC at the tip which appears like a ‘ball-pen’. The presence of MAC helps in the formation of sharp interference pattern that can be used for precise monitoring of RI. Using this procedure, three probes are fabricated with varying parameters. The maximum RI sensitivity is found to be 158.41 nm RIU −1 with resolution being 6....

中文翻译：

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基于微气腔的锥形尖端光子晶体光纤紧凑型折光仪

我们报告了一个紧凑而强大的微气腔（MAC）结合尖端锥形光子晶体光纤（PCF）的基于干涉仪点探头的折射率（RI）感应。将PCF的两个部分接合并逐渐变细，然后将锥形的塌陷部分劈开以形成尖端锥形PCF。PCF的一端接有单模光纤，而PCF的锥形尖端则经过激光微加工，这导致尖端形成了微沟槽。激光微加工即使在大致劈开的锥形部分上也能形成微槽。使用熔接机对微槽进行后期处理，以便在尖端形成MAC形，看起来像“圆珠笔”。MAC的存在有助于形成可以用于RI的精确监视的尖锐干扰模式。使用此过程，制作了三个具有不同参数的探头。发现最大RI灵敏度为158.41 nm RIU -1，分辨率为6 ....