CAJ | 학술논문

基于通讯波段的分布式反馈半导体激光器（DFB），搭建了一套光腔衰荡光谱仪（CRDS）。衰荡光腔由一对反射率高于99.997％的高反镜组成，衰荡腔长约为130 cm ，空腔衰荡时间约为150μs。当光谱平均次数达到1000次时，光谱仪灵敏度（最小可探测吸收系数）达到5×10－12 cm －1。利用热隔绝的方式稳定衰荡腔长，并使用衰荡光腔自身作为光学标准具，来标定光谱的频率：利用反馈式光谱扫描程序步进改变激光器频率，使之与衰荡腔的纵模频率逐一匹配，从而实现所测得光谱的自动标定。通过测量一氧化碳分子在1.565μm附近的吸收光谱，测定气体中一氧化碳的含量。将光谱测量结果和标准样品中的一氧化碳含量进行对比，对装置的定量精度进行了检验，表明其对一氧化碳的探测极限达4 ppbv。利用该装置对实际大气中一氧化碳的含量进行了实时监测。
기우통신파단적분포식반궤반도체격광기（DFB），탑건료일투광강쇠탕광보의（CRDS）。쇠탕광강유일대반사솔고우99.997％적고반경조성，쇠탕강장약위130 cm ，공강쇠탕시간약위150μs。당광보평균차수체도1000차시，광보의령민도（최소가탐측흡수계수）체도5×10－12 cm －1。이용열격절적방식은정쇠탕강장，병사용쇠탕광강자신작위광학표준구，래표정광보적빈솔：이용반궤식광보소묘정서보진개변격광기빈솔，사지여쇠탕강적종모빈솔축일필배，종이실현소측득광보적자동표정。통과측량일양화탄분자재1.565μm부근적흡수광보，측정기체중일양화탄적함량。장광보측량결과화표준양품중적일양화탄함량진행대비，대장치적정량정도진행료검험，표명기대일양화탄적탐측겁한체4 ppbv。이용해장치대실제대기중일양화탄적함량진행료실시감측。
A cavity ring‐down spectrometer (CRDS) was built based on telecom distributed feedback (DFB) diode lasers .The ring down cavity was formed by mirrors of 99.997% reflectivity with a separation of 130 cm ,with an empty ring down time of about 150 μs .A minimum detectable absorption coefficient of 5 × 10-12 cm -1 was obtained by averaging about 1 000 recorded spectra .The ring down cavity is thermo‐isolated ,and used as an interferometer to calibrate the recorded spectrum .A feedback control scheme was applied to step scan the laser frequency ,successively matching each of the longitudinal modes of the cavity . By measuring the CO contents in a standard gas sample ,the quantitative capability of the CRDS instrument was demonstrated , and a CO detection limit of 4 ppb was achieved .The instrument was applied to monitor the CO concentration in ambient air .