激光技术
激光技術
격광기술
LASER TECHNOLOGY
2015年
3期
304-307
,共4页
光纤光学%双通道调制光源%脉冲光%扫频光%布里渊频移%环形腔
光纖光學%雙通道調製光源%脈遲光%掃頻光%佈裏淵頻移%環形腔
광섬광학%쌍통도조제광원%맥충광%소빈광%포리연빈이%배형강
fiber optics%dual-channel modulation light source%pulse light%frequency sweep light%Brillouin frequency shift%ring cavity
为了满足布里渊光时域分析( BOTDA)光纤传感系统需要频差为布里渊频移的两种激光输出光源的需求,采用布里渊环形腔频移和电光调制的方法设计了双通道光源系统。根据光源的脉冲宽度、重复频率、扫频量等参量,对双通道调制光谱输出进行了仿真,并采用现场可编程门阵列配合直接数字式频率合成器技术的方案建立了系统实验装置,实现了脉冲探测光和扫频抽运光两种激光输出。脉冲探测光输出最小脉宽达10ns,扫频抽运光输出扫频范围达0MHz~90MHz,扫描频率步进值为30Hz,时间步进为1.6μs。结果表明,该光源技术参量满足BOTDA系统的要求,不需引入高频微波信号源等高速器件,信号采集模块可采用100MHz以下光电探测器件实现,降低了系统成本。
為瞭滿足佈裏淵光時域分析( BOTDA)光纖傳感繫統需要頻差為佈裏淵頻移的兩種激光輸齣光源的需求,採用佈裏淵環形腔頻移和電光調製的方法設計瞭雙通道光源繫統。根據光源的脈遲寬度、重複頻率、掃頻量等參量,對雙通道調製光譜輸齣進行瞭倣真,併採用現場可編程門陣列配閤直接數字式頻率閤成器技術的方案建立瞭繫統實驗裝置,實現瞭脈遲探測光和掃頻抽運光兩種激光輸齣。脈遲探測光輸齣最小脈寬達10ns,掃頻抽運光輸齣掃頻範圍達0MHz~90MHz,掃描頻率步進值為30Hz,時間步進為1.6μs。結果錶明,該光源技術參量滿足BOTDA繫統的要求,不需引入高頻微波信號源等高速器件,信號採集模塊可採用100MHz以下光電探測器件實現,降低瞭繫統成本。
위료만족포리연광시역분석( BOTDA)광섬전감계통수요빈차위포리연빈이적량충격광수출광원적수구,채용포리연배형강빈이화전광조제적방법설계료쌍통도광원계통。근거광원적맥충관도、중복빈솔、소빈량등삼량,대쌍통도조제광보수출진행료방진,병채용현장가편정문진렬배합직접수자식빈솔합성기기술적방안건립료계통실험장치,실현료맥충탐측광화소빈추운광량충격광수출。맥충탐측광수출최소맥관체10ns,소빈추운광수출소빈범위체0MHz~90MHz,소묘빈솔보진치위30Hz,시간보진위1.6μs。결과표명,해광원기술삼량만족BOTDA계통적요구,불수인입고빈미파신호원등고속기건,신호채집모괴가채용100MHz이하광전탐측기건실현,강저료계통성본。
For the purpose that a fiber sensor system of Brillouin optical time-domain analysis ( BOTDA) needs two light sources of Brillouin frequency shift , a dual-channel light source system was proposed by employing Brillouin ring cavity frequency shift and electro-optic modulation .According to several parameters , pulse width , repetition frequency rate and step of frequency sweeping , the output light spectrum of dual-channel modulation was simulated .Based on field programmable gate array ( FPGA) and direct digital synthesizer ( DDS) chip, experimental system was setup and both pulse detect light and sweep frequency pulse light could be output from the setup .The minimum pulse width of the detection pulse was 10ns, and the sweep frequency range reached 0MHz~90MHz with a frequency sweep step of 30Hz and a time step of 1.6μs.Experimental results show that the dual channel light source can meet the demands of general BOTDA systems, without the necessity of some high speed devices , such as high frequency microwave signal source .Signal acquisition modules can adopt regular photoelectric detectors below 100MHz so as to reduce the system cost .