DFB激光电流调制波长响应函数的确定及应用

发布时间：2018-04-04 19:11

本文选题：波长调制光谱　切入点：吸收光谱　出处：《北京交通大学》2017年硕士论文

【摘要】：波长调制技术(WMS)是现代气体痕量检测的重要手段之一,但在波长调制技术中,气体浓度的反演需要测量出无吸收时波长扫描的激光强度起伏、强度调制响应、扫描波长变化以及电流调制波长响应等来模拟出WMS光谱线型。其中电流调制波长响应信号的模拟,大大增加了技术的复杂性。截止目前,半导体激光的波长调制响应信号获得的方法均需要通过参数拟合,为了解决这一问题,实现零拟合参数,提出了基于扫描电流波长函数来确定电流调制波长响应函数的方法,本论文的主要工作如下:(1)在WMS技术的基础上,提出并发展了一种基于扫描电流波长函数确定DFB激光电流调制波长响应(CMWR)的方法,实现了 CMWR信号的免测量。通过将本文这种方法的结果与传统的三种方法的结果进行比较,验证了本文所提方法的准确性与精确性。其优势有:1)避免了常数法,一阶导数法和2f法过程对参数的拟合,实现了对波长调制响应信号的免测量,达到了零拟合参数的目标;2)对CMWR的描述精度高于常数法和一阶导数法,减小测量过程的复杂程度,简化了实验操作过程;3)可用于免定标测量法。(2)设计并搭建免定标波长调制光谱测量(CF-WMS)实验系统平台,将CMWR信号获取的新方法应用到免定标波长调制光谱测量技术中,并且使用Labview软件设计的双通道数字锁相放大器和滤波器对信号进行解调。基于1528nm的DFB激光器,使用CF-WMS对标配浓度的乙炔气体进行检测和监测,验证我们提出方法的准确性和可行性。
[Abstract]:Wavelength modulation technique (WMS) is one of the most important methods for the detection of trace gas. However, in the wavelength modulation technique, the inversion of gas concentration needs to measure the intensity fluctuation and intensity modulation response of wavelength scanning without absorption.Scanning wavelength variation and current modulation wavelength response are used to simulate the WMS spectral profile.The simulation of current modulation wavelength response signal greatly increases the complexity of technology.Up to now, the methods of obtaining the wavelength modulation response signal of semiconductor laser require parameter fitting. In order to solve this problem, zero fitting parameters are realized.A method to determine the wavelength response function of current modulation based on scanning current wavelength function is proposed. The main work of this paper is as follows: 1) based on WMS technology,A method for determining the wavelength response of DFB laser current modulation based on scanning current wavelength function is proposed and developed. The CMWR signal is realized without measurement.The accuracy and accuracy of the proposed method are verified by comparing the results of this method with those of the traditional three methods.The advantages include: 1) avoiding the constant method, the first order derivative method and the 2f method to fit the parameters, realizing the non-measurement of the wavelength modulation response signal, and achieving the goal of zero fitting parameters. The accuracy of describing the CMWR is higher than that of the constant method and the first order derivative method.It reduces the complexity of the measurement process and simplifies the experimental operation process. It can be used in the design and construction of a CF-WMS-based experimental system for non-calibration wavelength modulation spectral measurement.The new method of CMWR signal acquisition is applied to the spectrum measurement technique of non-scalable wavelength modulation, and the signal is demodulated by using the dual-channel digital phase-locked amplifier and filter designed by Labview software.The DFB laser based on 1528nm is used to detect and monitor the standard concentration of acetylene gas by using CF-WMS to verify the accuracy and feasibility of the proposed method.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN24

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