Based on local coupling mode theory of graded index optic fiber wave guide , the variation regularity of coupling output light has been deduced when sound wave acts on single mode optic fiber coupler . and a new idea has been proposed that a novel sensor can be applied on detection of acoustic / vibration . the sensing element of sensor is the melting area of single mode coupler in which the feasibility of the new - type optic fiber sensor has been proved in experiment 本文从缓变光纤波导的局部耦合模理论出发，推导出了单模光纤耦合器耦合分光在声波作用下的变化规律，提出了以单模光纤耦合器的熔融区为传感元件的传感器在声振动信号检测中应用的新思想，并实验论证了这种新型光纤传感器应用于实际的可行性。
The etching reactor is developed to obtain reproducible tapers of desired diameter and length . an approach for on - line monitoring of etching using the power meter is demonstrated . based on the experimental data , the relationship between the leak - out optical power and change of time and also that between the leak - out power and width of the remaining width of cladding , and the fiber length exposed to hf acid are summarized 本文对氢氟酸腐蚀法制作光纤耦合器的反应装置和实验系统进行了设计,介绍了具体的实验过程及其注意事项,通过对实验结果进行分析总结,得出泄漏光功率随腐蚀时间的变化关系以及泄漏光功率与包层剩余厚度和腐蚀长度的关系。
Before plastic optical fiber widespread application , each kind of plastic optical fiber coupler must be used surely , at present the important method to manufacture the plastic optical fiber coupler is fused elongated taper . if adopt this kind of method , the conversion efficiency between the core modes and the cladding modes is low . one of the methods to solve that is 在塑料光纤广泛应用之前必然运用到各种塑料光纤耦合器,目前熔融拉锥法是制备塑料光纤耦合器的重要方法,然而此种方法存在纤芯模与包层模的转换效率比较低的问题,解决这问题的一种方法是对塑料光纤进行热预拉锥。
In the beginning , the development history and the current development of the technique of fiber detection are introduced briefly . then , discussed in detail are strong coupling theory concerning the fbt coupler and the weak coupling theory concerning the hf acid etching and the side - polishing coupler . from the analysis of fiber coupling equations , the solution of the equation and the formula of the coupling coefficient are derived 本文首先概述了光纤窃听技术的发展历程和现状,有针对性地分析了关于光纤窃听技术中的光纤耦合问题,并详细介绍了用于熔融拉锥耦合器的强耦合理论和用于氢氟酸腐蚀与边研磨光纤耦合器的弱耦合理论;分析了耦合模方程,得出了耦合模方程的形式解,推导出耦合系数的计算公式。
