CAJ | 학술논문

可调谐二极管激光吸收光谱在诸多领域有广泛的应用，但因为基线获取的困难，在高压、强干扰条件下的测量存在困难。波长调制光谱的理论显示，一次谐波信号(1f)和二次谐波信号(2f)包含了初始光强和光电探测器增益两个公共项。通过一次谐波信号归一化的二次谐波(2f/1f)信号，消除了信号强度与光强的相关性，可得到吸收光谱的绝对强度及温度等信息。通过测量激光调制参数，结合已知光谱参数可通过数值仿真得到理论的2f/1f信号。利用数值锁相算法，可以实现频分复用的免标定波长调制光谱测量，实验显示，当恒温池设定温度为600 K、700 K和800 K时，光谱测量温度与热电偶测量值偏差小于2%，该方法具有可靠性和更强适应性。
가조해이겁관격광흡수광보재제다영역유엄범적응용，단인위기선획취적곤난，재고압、강간우조건하적측량존재곤난。파장조제광보적이론현시，일차해파신호(1f)화이차해파신호(2f)포함료초시광강화광전탐측기증익량개공공항。통과일차해파신호귀일화적이차해파(2f/1f)신호，소제료신호강도여광강적상관성，가득도흡수광보적절대강도급온도등신식。통과측량격광조제삼수，결합이지광보삼수가통과수치방진득도이론적2f/1f신호。이용수치쇄상산법，가이실현빈분복용적면표정파장조제광보측량，실험현시，당항온지설정온도위600 K、700 K화800 K시，광보측량온도여열전우측량치편차소우2%，해방법구유가고성화경강괄응성。
Tunable diode laser absorption spectroscopy is widely used in many applications,with difficulty of abstracting baseline,it is hard to be used in high-pressure and high-disturbing conditions. It′s indicated in theory of wavelength-modulation spectroscopy that the first and second order harmonic signals contain tow common terms: incident intensity and gain of detector . By normalizing 2f signal with 1f signal ( 2f/1f ), dependency of 2f/1f signal on incident intensity was eliminated, absolute strength of a spectra can be obtained subsequently. With measured laser parameter and known spectral parameters, theoretical 2f/1f signal was simulated by numerical calculation. Calibration-free wavelength-modulation spectroscopy was built based on frequency demultiplexing method, by numeric lock-in code. When a temperature stabilized cell was set at 600 K, 700 K, 800 K, precision of 2% is achieved compared with thermocouple measurement, which indicates that the method is much more reliable and adaptable.