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gentle_man: 金幣+5, ★★★很有幫助, 謝謝回答 2015-10-26 10:55:37
吸收帶
基于多波段混合氣體吸收譜線的波長標定方法研究
https://www.joelcn.com/ch/reader ... px?file_no=20140622
中文摘要:
為實現(xiàn)光纖掃描光源寬調(diào)諧范圍內(nèi)輸出波長的高 精度標定,提出了一種基于多波段混合氣體吸收譜 線的波長標定方法。采用分段閾值二階導極值法和洛倫茲線型擬合法從混合氣體吸收光譜中 提取多條譜線 中心位置,以其波長和驅(qū)動電壓為參考點對Fabry-Perot(F-P)可調(diào)諧濾波器的遲滯非 線性特性進行二次多項式擬合標定。 將C2H2在C波段的吸收帶與CO2在L波段的吸收帶相結(jié)合,選取了21條C2H 2譜線和16條CO2譜線作為波長參考。將本方法用于C+L波段的光纖光柵(FBG )波長解調(diào),在0～60 ℃范圍內(nèi)波長擬 合標準差小于3.3pm,線性相關系數(shù)大于0.999,系統(tǒng)穩(wěn)定性誤差小于2.6pm。
英文摘要:
In order to recognize the output wavelength of fiber swept source prec isely in a wide tuning range,a wavelength calibrating method based on mixed gas absorption lines in mu ltiple near -infrared bands is proposed. Second derivative extremum with segmented threshold and Lorentzian line shape fi tting are used to extract the accurate center positions of multiple absorption lines from mixed gas absorption spectrum.The absorption wavelengths and their corresponding drive voltages can be adopted as stable refe rence points to calibrate the nonlinear characteristics of the fiber Farby-Perot tunable filter.The nonlinear ity is usually described using second order polynomial due to the small fitting error.In this paper,the absorption branch of acetylene in C-band and that of carbon dioxide in L-band are combined to provide wavelength reference.21absor ption lines of acetylene and 16absorption lines of carbon dioxide are selected respectively according to the ab sorption intensity.When the proposed wavelength calibrating method is applied to get the wavelength s of FBG string in C+L band,the standard deviation of wavelength linear fitting in the temperature range from 0℃ to 60℃ is no more than 3.3pm and the linear correlation coefficient is larger than 0.9998.The syst em has a good stab ility with a repeatability standard deviation less than 2.6pm. |
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