Author Affiliations
Abstract
1 College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha 410073, China
2 State Key Laboratory of Pulsed Power Laser Technology, Changsha 410073, China
3 Hunan Provincial Key Laboratory of High Energy Laser Technology, Changsha 410073, China
4 Tianjin Navigation Instruments Research Institute, Tianjin 300131, China
We propose here a novel method for position fixing in the micron scale by combining the convolutional neural network (CNN) architecture and speckle patterns generated in a multimode fiber. By varying the splice offset between a single mode fiber and a multimode fiber, speckles with different patterns can be generated at the output of the multimode fiber. The CNN is utilized to learn these specklegrams and then predict the offset coordinate. Simulation results show that predicted positions with the precision of 2 μm account for 98.55%. This work provides a potential high-precision two-dimensional positioning method.
fiber optics fiber optics sensors fiber optics imaging Chinese Optics Letters
2020, 18(5): 050602
采用石英增强光声光谱检测系统，并引入空芯光子晶体光纤作为气体参考气室，实现对痕量氨气的高灵敏度检测。参考气室采用长5 m 的空芯光子晶体光纤，两端熔接单模光纤，内部填充标准氨气。通过分析空芯光子晶体光纤的模态干涉，获得低干涉噪声的透射谱。气体填充过程中，控制填充压强与时间，提高谱线分辨率，完成分布反馈式(DFB)激光器波长的精确锁定，提高检测精度。测量参考气体腔内氨气吸收谱线线宽，并与高分辨率光谱谱线(HITRAN)数据库数据对比验证实验结果。采用光声光谱检测系统，优化调制参数，获得氨气噪声等效浓度(即指体积分数)为6.74×10-6(3σ)。
光谱学 光声光谱 气体传感 空芯光子晶体光纤 气体参考腔 石英音叉
增强石英音叉光声光谱技术作为光声光谱探测技术的一种，具有高灵敏度、高选择性、响应速度快的优势。增强石英音叉光声光谱技术采用可调谐石英音叉代替光声吸收单元和麦克风来实现光声信号探测，微共振管用来增强信号。分析并比较了三种音叉与微共振管耦合方式的增强石英音叉光声探测器，分析了影响系统信号强度与信噪比的因素，并总结了在参数优化方面的进展。在此分析基础上，介绍研制的小型化光声探测器装置和一种新型的太赫兹增强石英音叉光声探测器，并对其采用的定制音叉参数进行分析。随着新型中红外激光光源的应用，石英音叉光声探测装置会逐渐摆脱光束质量对其的限制，得到更广泛应用。
探测器 石英增强光声光谱 石英音叉 微谐振器 光声探测装置 激光与光电子学进展
2015, 52(9): 090002
