本文使用火焰熔融拉锥的方法，通过控制火焰的高度及拉锥速度，成功制备了具有微拱型渐变区的新型微纳光纤器件。理论计算表明，微拱型渐变区有利于激发出强度相当的高阶微纳光纤传输模式，从而增加了传输光谱中由模间干涉导致的透射谷的深度。实验表明，该新型微纳光纤器件透射谷深度达到18 dB，当轴向应变量增加时，透射谷向短波长方向移动，轴向应变灵敏度为-13.1 pm/με，比光纤光栅应变传感器提高一个数量级，是传统直线型微纳光纤灵敏度的3倍，线性度为99.15%。这种具有微拱型渐变区的微纳光纤器件具有灵敏度高、机械性能好以及便于与现有光纤系统集成等优点。并且结构简单，易于制备，可广泛应用于各种物理、化学和生物传感和探测领域。

A microfiber strain sensor with arched transition region was demonstrated. By controlling the flame size and tapering speed, a novel micro fiber with arched transition region was successfully fabricated. Consid-erable high order propagation modes of microfiber were excited by the arched transition region, resulting in in-creasing the depth of valley in the transmission spectrum of microfiber. The depth of the transmission valley is up to 18dB. Furthermore, when the axial strain increased, the position of the transmission valley was blue shift, the linearity is 99.15% and the axial strain sensitivity was -13.1 pm/με, which was one order magnitude larger than that of traditional fiber strain sensors based on Bragg grating. This kind of microfiber with arched transition region has many advantages, such as high sensitivity, good mechanical performance, compatibility to traditional optical fiber systems, and easy to be fabricated. It can be widely used in various physical, chemical and biological sens-ing and detection fields.