电光晶体材料包层光纤Bragg光栅及其传感应用的研究

发布时间：2018-05-08 07:34

本文选题：光纤Bragg光栅 + 色散　；参考：《兰州理工大学》2017年硕士论文

【摘要】：本文提出了一种包层为电光晶体材料LiTaO3的新型光纤Bragg光栅,结合电光效应、耦合模理论和同时测量原理等理论,分析了纤芯半径和外加电场对光栅特性的影响并应用该类型光栅设计了一种新型传感器。主要研究内容如下:1、研究了芯径半径大小和电场强度对基模能量分布、布拉格波长?B、反射率?、群时延?、二阶色散D和三阶色散?3的影响。研究结果表明:(1)半径恒定条件下,随着电场强度的不断增加,基模能量最大值也增加,有效模场面积和光栅布拉格波长不断减小,反射谱、群时延和二阶色散曲线都向短波长方向移动,期间伴随着反射谱宽度、最大值和最小值的改变,并且布拉格波长处的时延最大,二阶色散最小。(2)入射波长恒定条件下,当半径增加时,反射谱、群时延和二阶色散曲线移向高电场,当电场强度增加时,与反射谱、群时延和二阶色散曲线对应的半径也增大。(3)电场一定时,随着半径a的逐渐增大时延最大值向长波长移动,即发生红移,并且半径对时延的影响程度与电场强度的大小有关。(4)当波长?=1550nm,半径为900nm,电场强度为53×107 v/m时,三阶色散?3取得最大值。?3从最小值到最大值的过程中,电场强度改变了1×106v/m,而半径只改变了0.1nm,该结果说明三阶色散对电场不是很敏感,但是其对半径极为敏感。2、设计了一种包层为单轴电光晶体LiTaO3的新型光纤Bragg光栅传感器。单个光纤Bragg光栅的一半包层被施加电场,另一半保持不变,应用耦合模理论、电光效应原理和双波长法研究了有外加电场时的传感性能。研究结果表明没有电场的一半光栅的温度灵敏度为14.31 pm/℃,与之对应的布拉格波长漂移只与温度或者应变有关;所加电场强度在0-400×107v/m之间时,有电场的一半光栅的温度灵敏度变化范围为14.12-14.31 pm/℃,与之对应的布拉格波长漂移不仅与温度或者应变有关,还受到电场强度的影响。因此,应用该传感器可分辨出温度、电场强度所引起的布拉格波长漂移,从而实现了温度-电场的同时测量。该成果在高电压领域具有潜在的应用价值。
[Abstract]:In this paper, a new type of fiber Bragg grating with a coating of electrooptic crystal material LiTaO3 is proposed. Combining the electro-optic effect, the coupled mode theory and the simultaneous measurement principle, the influence of the core radius and the applied electric field on the characteristics of the grating is analyzed and a new type of sensor is designed with this type of grating. The main contents are as follows: 1, the study is made. The radius of the core diameter and the intensity of the electric field are affected by the energy distribution of the base mode, Prague wavelength? B, reflectivity, group delay?, the two order dispersion D and the three order dispersion? 3. The results show: (1) under constant radius, the maximum value of the base mode energy increases with the constant increase of the electric field intensity, and the effective mode field area and the grating wavelength of the grating decrease continuously. The reflection spectrum, the group delay and the two order dispersion curve are all moving in the short wavelength direction, with the change of the width of the reflection spectrum, the maximum and the minimum, and the maximum time delay at the Prague wavelength and the least two order dispersion. (2) when the incident wavelength is constant, the reflection spectrum, the group delay and the two order dispersion curve move to the high electric field when the radius is constant. When the intensity of the electric field is increased, the radius corresponding to the reflection spectrum, group delay and the two order dispersion curve also increases. (3) when the electric field is fixed, the maximum time delay of the radius a moves to the long wavelength, that is, the red shift occurs, and the influence of the radius on the time delay is related to the intensity of the electric field. (4) when the wavelength is =1550nm, the radius is 900nm, the electric field is strong. When the degree is 53 x 107 v/m, the three order dispersion 3 obtains the maximum value.? 3 from the minimum to the maximum value, the electric field intensity changes 1 x, and the radius only changes 0.1nm. The result shows that the three order dispersion is not very sensitive to the electric field, but it is very sensitive to the radius of the radius, and a new type of fiber Bra with the uniaxial electro-optic crystal LiTaO3 is designed. GG grating sensor. The half cladding of a single fiber Bragg grating is applied electric field and the other half remains unchanged. Using the coupled mode theory, the electro-optic effect principle and the double wavelength method, the sensing performance of the applied electric field is studied. The results show that the temperature sensitivity of the half grating without electric field is 14.31 pm/ C, and the corresponding Prague wave The long drift is only related to temperature or strain; when the intensity of the electric field is 0-400 * 107v/m, the temperature sensitivity of the half grating with an electric field is 14.12-14.31 pm/ C. The corresponding Prague wavelength shift is not only related to the temperature or strain, but also influenced by the electric field intensity. Therefore, the sensor can be resolved by using the sensor. The temperature and electric field intensity caused by the Prague wavelength drift, thus achieving the simultaneous measurement of the temperature electric field. The results have potential application value in the field of high voltage.

【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN253;TP212

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