高精细度微透镜光纤法布里-珀罗干涉仪

High-Finesse Micro-Lens Optical Fiber Fabry-Perot Interferometers

通过在镀膜单模光纤端面制作微透镜,构造了微透镜光纤法布里-珀罗干涉仪。利用ABCD矩阵方法分析了微透镜法布里-珀罗腔的模场。由于微透镜的会聚作用,法布里-珀罗腔模场可以和单模光纤模场良好的匹配,从而达到高精细度和低插入损耗。实验制作的微透镜光纤法布里-珀罗干涉仪。自由光谱区范围32.28 nm,精细度为78,峰值透射比为73%;在法布里-珀罗腔的光学腔长增加到100 μm的情况下,峰值透射比仍然大于50%。该微透镜光纤法布里-珀罗干涉仪制作容易、对设备要求低,可以封装成光纤法布里-珀罗滤波器和传感器,具有广泛的应用前景。

A micro-lens optical fiber Fabry-Pérot interferometer is demonstrated by manufacturing micro-lenses on the mirrored endfaces of two single-mode optical fibers. The mode field of the Fabry-Pérot cavity is theoretically calculated by using ABCD matrix method. The mode field of the Fabry-Pérot cavity matches that of a single-mode optical fiber very well due to the focusing of micro-lenses, thus resulting in high finesse and low insertion loss. A micro-lens optical fiber Fabry-Pérot interferometer with free spectral range of 32. 28 nm, finesse of 78 and peak transmittance of 73 % is experimentally demonstrated. It can maintain a peak transmittance better than 50 %, even if the optical cavity length of the Fabry-Pérot cavity is increased to 100 μm. This kind of micro-lens optical fiber Fabry- Pérot interferometer is easy to build, and can be used as optical fiber Fabry-Pérot filters and high-finesse optical fiber Fabry-Pérot sensors.