Ayerden N Pelin, Mandon Julien, Harren Frans J M, Wolffenbuttel Reinoud F
Electronic Instrumentation Laboratory, Microelectronics Department, Faculty of EEMCS, Delft University of Technology, Mekelweg 4, 2628 CD Delft, The Netherlands.
Life Science Trace Gas Research Group, Department of Molecular and Laser Physics, Institute for Molecules and Materials, Radboud University Nijmegen, Heijendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
Sensors (Basel). 2017 Sep 6;17(9):2041. doi: 10.3390/s17092041.
Increasing demand for field instruments designed to measure gas composition has strongly promoted the development of robust, miniaturized and low-cost handheld absorption spectrometers in the mid-infrared. Efforts thus far have focused on miniaturizing individual components. However, the optical absorption path that the light beam travels through the sample defines the length of the gas cell and has so far limited miniaturization. Here, we present a functionally integrated linear variable optical filter and gas cell, where the sample to be measured is fed through the resonator cavity of the filter. By using multiple reflections from the mirrors on each side of the cavity, the optical absorption path is elongated from the physical m m -level to the effective m m -level. The device is batch-fabricated at the wafer level in a CMOS-compatible approach. The optical performance is analyzed using the Fizeau interferometer model and demonstrated with actual gas measurements.
对用于测量气体成分的现场仪器需求的不断增加，有力地推动了中红外波段坚固、小型化且低成本手持式吸收光谱仪的发展。迄今为止，工作重点一直是使各个组件小型化。然而，光束穿过样品的光吸收路径决定了气室的长度，并且迄今为止限制了小型化。在此，我们展示了一种功能集成的线性可变光学滤波器和气室，其中待测样品通过滤波器的谐振腔馈入。通过利用腔两侧镜面上的多次反射，光吸收路径从物理毫米级延长到有效毫米级。该器件采用与CMOS兼容的方法在晶圆级进行批量制造。使用菲佐干涉仪模型分析光学性能，并通过实际气体测量进行了演示。
