Physics Department, University of Ioannina, 45110 Ioannina, Greece.
Department of Medical Physics, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece.
Sensors (Basel). 2020 Apr 28;20(9):2503. doi: 10.3390/s20092503.
Using either bulk or fiber optics the profile of laser beams can be altered from Gaussian to top-hat or hollow beams allowing enhanced performance in applications like laser cooling, optical trapping, and fiber sensing. Here, we report a method based on multimode Plastic Optical Fibers (POF) long-tapers, to tweak the beam profile from near Gaussian to a hollow beam, by generating surface irregularities on the conical sections of the taper with a heat-and-pull technique. Furthermore, a cutback technique applied on long tapers expanded the output beam profile by more than twice the numerical aperture (NA) of the fiber. The enhanced sensitivity and detection efficiency of the extended profile was tested on a fiber optical ice sensor related to aviation safety.
使用体光纤或光纤，激光束的轮廓可以从高斯分布改变为平顶或中空光束，从而在激光冷却、光学捕获和光纤传感等应用中提高性能。在这里，我们报告了一种基于多模塑料光纤（POF）长渐变光纤的方法，通过在渐变光纤的锥形部分上使用热拉伸技术产生表面不规则性，将光束轮廓从近高斯分布调整为中空光束。此外，在长渐变光纤上应用截断技术，将输出光束轮廓扩展超过光纤数值孔径（NA）的两倍。扩展后的轮廓在与航空安全相关的光纤光学冰传感器上进行了灵敏度和检测效率测试。
