摘要
基于布里渊散射的分布式光纤传感技术是目前国内外研究的热点之一,在基于布里渊光时域反射技术的分布式光纤传感技术中,以相干检测的传感精度最高,其关键是获得具有布里渊频移的参考光。详细分析了电光强度调制器(EOIM)的光波移频特性,实验研究了15 Gbit/s的铌酸锂波导电光强度调制器光波长1550 nm处11 GHz移频的实现;当微波调制频率及功率一定时,可方便地调节直流偏置电压来改变各阶光波的强度。设置直流偏置电压为6.5 V时,调制器总的输出光强最小,具有布里渊频移的一阶光波的相对光强最大,信噪比(SNR)最高,可用于分布式光纤传感中布里渊信号的相干检测。
Distributed optical fiber sensing based on Brillouin scattering is one of the subjects of intensive investigation all over the world at present. For the distributed fiber sensing based on Brillouin optical time-domain reflectometry, the heterodyne detection achieves the highest sensing resolution, and the key problem is how to obtain the referenced light with Brillouin frequency shift. The principle of frequency shift based on LiNbO3 waveguide electro-optic intensity modulator （EOIM） is analyzed in detail. The 11 GHz frequency shift at 1550 nm is obtained experimentally with a 15 Gbit/s LiNbO3 waveguide. It is convenient to change the optical intensity of the sidebands by tuning the DC bias voltage while the microwave modulation frequency and power are fixed. Particularly, when the DC bias voltage is set to 6.5 V, the modulator achieves minimum total output optical intensity, and the first sideband with Brillouin frequency shift reachs the maximums relative intensity and signal-to-noise ratio （SNR）. These results can be used for Brillouin heterodyne detection in the distributed optical fiber sensing.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2009年第4期901-905,共5页
Chinese Journal of Lasers
基金
新世纪优秀人才项目(NCET-06-0925)资助课题
关键词
光电子学
光波移频
铌酸锂波导电光强度调制器
布里渊分布式光纤传感技术
optoelectronics
optical frequency shift
LiNbO3 waveguide electro-optic intensity modulator
distributed Brillouin optical fiber sensing
