Li Jinyang, Lu Dan-feng, Qi Zhi-mei
State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, China.
Appl Spectrosc. 2015 Sep;69(9):1112-7. doi: 10.1366/14-07851.
A prototype stationary Fourier transform spectrometer (FTS) was constructed with a fiber-coupled lithium niobate (LiNbO3) waveguide Mach-Zehnder interferometer (MZI) for the purpose of rapid on-site spectroscopy of biological and chemical measurands. The MZI contains push-pull electrodes for electro-optic modulation, and its interferogram as a plot of intensity against voltage was obtained by scanning the modulating voltage from -60 to +60 V in 50 ms. The power spectrum of input signal was retrieved by Fourier transform processing of the interferogram combined with the wavelength dispersion of half-wave voltage determined for the MZI used. The prototype FTS operates in the single-mode wavelength range from 1200 to 1700 nm and allows for reproducible spectroscopy. A linear concentration dependence of the absorbance at λmax = 1451 nm for water in ethanolic solution was obtained using the prototype FTS. The near-infrared spectroscopy of solid samples was also implemented, and the different spectra obtained with different materials evidenced the chemical recognition capability of the prototype FTS. To make this prototype FTS practically applicable, work on improving its spectral resolution by increasing the maximum optical path length difference is in progress.
构建了一种原型静态傅里叶变换光谱仪（FTS），它采用光纤耦合铌酸锂（LiNbO₃）波导马赫曾德尔干涉仪（MZI），用于对生物和化学被测量物进行快速现场光谱分析。该MZI包含用于电光调制的推挽电极，通过在50毫秒内将调制电压从-60 V扫描到+60 V，获得了其作为强度与电压关系图的干涉图。通过对干涉图进行傅里叶变换处理，并结合所使用MZI的半波电压的波长色散，检索出输入信号的功率谱。该原型FTS在1200至1700 nm的单模波长范围内运行，并可实现可重复的光谱分析。使用该原型FTS获得了乙醇溶液中水在λmax = 1451 nm处吸光度的线性浓度依赖性。还实现了固体样品的近红外光谱分析，不同材料获得的不同光谱证明了该原型FTS的化学识别能力。为使该原型FTS实际可用，目前正在通过增加最大光程差来提高其光谱分辨率的工作。
