Li Jinyang, Lu Dan-feng, Qi Zhi-mei
Opt Lett. 2014 Jul 1;39(13):3923-6. doi: 10.1364/OL.39.003923.
A simple and reliable spectrum-retrieval method was proposed for the development of miniature stationary Fourier transform (FT) spectrometers based on a LiNbO₃ (LN) waveguide Mach-Zehnder interferometer (MZI) modulator. The method takes into account the wavelength dependence of the optical pathlength difference (OPD) and allows us to use a nonlinear voltage ramp to modulate the OPD. The method is based on the dispersion of the half-wave voltage, which was measured to be a monotonous polynomial function of the wavelength for the LN waveguide MZI used. With the measured dispersion of the half-wave voltage, the OPD, as a linear function of the modulating voltage, can be accurately determined at each wavelength in the near-infrared region in which the MZI used is a single-mode device. A prototype FT spectrometer was prepared using a LN waveguide MZI modulator based on the above method. The experimental results demonstrated that the spectrometer can be used for accurate determination of the laser wavelength and for liquid absorptiometry.
提出了一种简单可靠的光谱检索方法，用于基于铌酸锂（LN）波导马赫-曾德尔干涉仪（MZI）调制器开发微型静态傅里叶变换（FT）光谱仪。该方法考虑了光程差（OPD）的波长依赖性，并允许我们使用非线性电压斜坡来调制OPD。该方法基于半波电压的色散，对于所使用的LN波导MZI，测量得到半波电压是波长的单调多项式函数。利用测量得到的半波电压色散，作为调制电压线性函数的OPD可以在近红外区域的每个波长处精确确定，在所使用的MZI为单模器件的该近红外区域。基于上述方法，使用LN波导MZI调制器制备了一台FT光谱仪原型。实验结果表明，该光谱仪可用于精确测定激光波长和液体吸光测定。
