Laboratory of Optics, Lasers and Systems, Faculty of Sciences, University of Lisbon, Lisboa, Portugal.
Sensors (Basel). 2013 Aug 12;13(8):10333-47. doi: 10.3390/s130810333.
In the last years, mid-infrared radiation emitted by CO2 lasers has become increasing popular as a tool in the development of long-period fiber gratings. However, although the development and characterization of the resulting sensing devices have progressed quickly, further research is still necessary to consolidate functional models, especially regarding the interaction between laser radiation and the fiber's material. In this paper, a 3D finite element model is presented to simulate the interaction between laser radiation and an optical fiber and to determine the resulting refractive index change. Dependence with temperature of the main parameters of the optical fiber materials (with special focus on the absorption of incident laser radiation) is considered, as well as convection and radiation losses. Thermal and residual stress analyses are made for a standard single mode fiber, and experimental results are presented.
在过去的几年中，CO2 激光发射的中红外辐射作为长周期光纤光栅开发的工具变得越来越受欢迎。然而，尽管由此产生的传感设备的开发和特性研究进展迅速，但仍需要进一步的研究来巩固功能模型，特别是关于激光辐射与光纤材料之间的相互作用。在本文中，提出了一个三维有限元模型来模拟激光辐射与光纤之间的相互作用，并确定由此产生的折射率变化。考虑了光纤材料的主要参数（特别关注入射激光辐射的吸收）与温度的依赖性，以及对流和辐射损耗。对标准单模光纤进行了热和残余应力分析，并给出了实验结果。
