Gattinger Paul, Zorin Ivan, Rankl Christian, Brandstetter Markus
RECENDT-Research Center for Non-Destructive Testing GmbH, Science Park 2, Altenberger Str. 69, 4040 Linz, Austria.
Sensors (Basel). 2021 Aug 18;21(16):5563. doi: 10.3390/s21165563.
In this contribution, we present a high-speed, multiplex, grating spectrometer based on a spectral coding approach that is founded on principles of compressive sensing. The spectrometer employs a single-pixel InGaAs detector to measure the signals encoded by an amplitude spatial light modulator (digital micromirror device, DMD). This approach leads to a speed advantage and multiplex sensitivity advantage atypical for standard dispersive systems. Exploiting the 18.2 kHz pattern rate of the DMD, we demonstrated 4.2 ms acquisition times for full spectra with a bandwidth of 450 nm (5250-4300 cm; 1.9-2.33 µm). Due to the programmability of the DMD, spectral regions of interest can be chosen freely, thus reducing acquisition times further, down to the sub-millisecond regime. The adjustable resolving power of the system accessed by means of computer simulations is discussed, quantified for different measurement modes, and verified by comparison with a state-of-the-art Fourier-transform infrared spectrometer. We show measurements of characteristic polymer absorption bands in different operation regimes of the spectrometer. The theoretical multiplex advantage of 8 was experimentally verified by comparison of the noise behavior of the spectral coding approach and a standard line-scan approach.
在本论文中，我们展示了一种基于光谱编码方法的高速、多路复用光栅光谱仪，该方法基于压缩感知原理。该光谱仪采用单像素铟镓砷探测器来测量由幅度空间光调制器（数字微镜器件，DMD）编码的信号。这种方法带来了速度优势和多路复用灵敏度优势，这对于标准色散系统来说是不典型的。利用DMD的18.2kHz图案速率，我们展示了对于带宽为450nm（5250 - 4300cm⁻¹；1.9 - 2.33μm）的全光谱，采集时间为4.2ms。由于DMD的可编程性，可以自由选择感兴趣的光谱区域，从而进一步将采集时间缩短至亚毫秒级。通过计算机模拟讨论了系统的可调分辨率，针对不同测量模式进行了量化，并与一台先进的傅里叶变换红外光谱仪进行比较进行了验证。我们展示了在光谱仪不同工作模式下对特征聚合物吸收带的测量。通过比较光谱编码方法和标准线扫描方法的噪声行为，从实验上验证了理论上8倍的多路复用优势。
