CAJ | 학술논문

将光纤光栅的傅里叶模式耦合理论应用于光纤布拉格光栅型全光纤声光调制器的理论分析中.与现有的分析方法相比,该模型算法简单、求解容易,能够快速有效地获得调制器的传输特性.基于该模型,理论分析了超声波频率及声致应变幅度对调制器特性的影响.仿真结果表明,该调制器反射谱的主反射峰与次反射峰的波长间隔与超声波频率成正比,反射峰的反射率随着声致应变幅度的改变而发生周期性的变化.另外,在同一声致应变幅度下,低频超声波调制的光栅反射中存在更多的次反射,光栅反射能量的周期性变化更加明显.实验中,使用频率为885.5 kHz的超声波对光纤布拉格光栅进行调制.实验结果与仿真结果相一致.
장광섬광책적부리협모식우합이론응용우광섬포랍격광책형전광섬성광조제기적이론분석중.여현유적분석방법상비,해모형산법간단、구해용역,능구쾌속유효지획득조제기적전수특성.기우해모형,이론분석료초성파빈솔급성치응변폭도대조제기특성적영향.방진결과표명,해조제기반사보적주반사봉여차반사봉적파장간격여초성파빈솔성정비,반사봉적반사솔수착성치응변폭도적개변이발생주기성적변화.령외,재동일성치응변폭도하,저빈초성파조제적광책반사중존재경다적차반사,광책반사능량적주기성변화경가명현.실험중,사용빈솔위885.5 kHz적초성파대광섬포랍격광책진행조제.실험결과여방진결과상일치.
The Fourier mode coupling theory is applied to the analysis of the fiber Bragg grating based all-fiber acousto-optic modulator for the first time. Compared with the existing analysis methods, the algorithm of this model is simple and easy, and transmission characteristics of the modulator can be acquired effectively and efficiently. Based on the theory, the performances of the modulator, related to ultrasonic frequency and amplitude of acoustically induced strain, are investigated. Simulation results show that in reflection spectra of the modulator, the wavelength interval between the primary relection peak and the secondary relection peak is proportional to ultrasonic frequency, and the reflectivity of the reflection peak varies periodically with intensity change of the amplitude of acoustically induced strain. In addition, with the same amplitude of acoustically induced strain, more secondary reflections exist in the low-frequency ultrasonic modulated fiber Bragg grating, and the periodic variation of the energy reflected by fiber Bragg graing is more obvious. In the experiment, the fiber Bragg graing is modulated by an ultrasonic wave with a frequency of 885.5 KHz. The experimental results accord well with the simulation results.