以直线形光纤马赫曾德尔干涉仪作为滤波器件, 掺铒光纤作为增益介质的环行腔光纤激光器实现位移传感。构成该马赫曾德尔干涉仪的扩径光纤锥由光纤熔接机制作而成。随着两个应力调节支架距离的减小, 干涉仪发生弯曲, 输出的波峰向短波长方向移动, 最大敏感度为4.49 nm/mm, 消光比大于50 dB。扩径光纤锥的引入使得光纤在弯曲时能够保持基本一致的弯曲度, 并且相比其他结构强度更高, 不容易发生断裂。同时, 该结构的制作所需材料便宜, 制作过程简便, 有利于工程应用。

A ring cavity fiber laser based on the filter of up-tapered Mach-Zehnder interferometer(MZI) was proposed and demonstrated for displacement sensor experimentally. The up-tapered MZI was easily fabricated by using a commercial fusion splicer. The peak wavelength of the laser bule-shifted with the different bending direction by decreasing the distance between the two stages. The maximum sensitivity of 4.49 nm/mm and extinction ratio of more than 50 dB were achieved. The configuration of up-tapers were strong in strength, therefore, the bending radius of the whole fiber were almost the same. Note that this kind of configuration is easy in fabrication and low in cost which is beneficial for engineering application.