Environmental mid-infrared gas sensing using MEMS FTIR spectrometer

In this work, we report carbon dioxide gas sensing in the ambient air in the mid-infrared range around 4250 nm using MEMS FTIR spectrometer. The core engine of the spectrometer is a scanning Michelson interferometer fabricated using deep etching technology on silicon-on-insulator wafer. The measured Signal-to-Noise Ratio (SNR) is 24 dB at a wavelength of 4250 nm and the spectral resolution is about 60 cm-1. A free-space gas cell using CaF2 lenses with lightgas interaction lengths of 12 cm and 120 cm is demonstrated. The results demonstrate about 400 ppm concentration detection in the ambient air. The theoretical sensitivity limit based on the achieved SNR and resolution is about 15 ppm.

[1]  Yasser M. Sabry,et al.  Characterization of MEMS FTIR spectrometer , 2011, MOEMS-MEMS.

[2]  Yasser M. Sabry,et al.  On the environmental gas sensing using MEMS FTIR spectrometer in the near-infrared region , 2016, 2016 33rd National Radio Science Conference (NRSC).

[3]  K. Sharaf,et al.  Mid infrared MEMS FTIR spectrometer , 2016, SPIE OPTO.

[4]  Yasser M. Sabry,et al.  Novel Fourier transform infrared spectrometer architecture based on cascaded Fabry-Perot interferometers , 2016, SPIE OPTO.

[5]  T. Bourouina,et al.  Monolithic silicon‐micromachined free‐space optical interferometers onchip , 2015 .

[6]  Daqiang Zhang,et al.  A Survey on Gas Sensing Technology , 2012, Sensors.

[7]  F. Marty,et al.  MEMS tunable Michelson interferometer with robust beam splitting architecture , 2009, 2009 IEEE/LEOS International Conference on Optical MEMS and Nanophotonics.

[8]  Diaa Khalil,et al.  Wideband Optical MEMS Interferometer Enabled by Multimode Interference Waveguides , 2016, Journal of Lightwave Technology.

[9]  Diaa Khalil,et al.  On-Chip Micro–Electro–Mechanical System Fourier Transform Infrared (MEMS FT-IR) Spectrometer-Based Gas Sensing , 2016, Applied spectroscopy.

[10]  Yasser M. Sabry,et al.  High-throughput deeply-etched scanning Michelson interferometer on-chip , 2014, 2014 International Conference on Optical MEMS and Nanophotonics.

[11]  F. Marty,et al.  Mechanical displacement multiplier: 250 μM stable travel range MEMS actuator using frictionless simple compliant structures , 2012, 2012 IEEE 25th International Conference on Micro Electro Mechanical Systems (MEMS).

[12]  Yasser M. Sabry,et al.  MMI-based MOEMS FT spectrometer for visible and IR spectral ranges , 2014, Photonics West - Micro and Nano Fabricated Electromechanical and Optical Components.

[13]  Diaa A Khalil,et al.  Signal-to-noise ratio calculation in a moving-optical-wedge spectrometer. , 2012, Applied optics.

[14]  Yasser M. Sabry,et al.  Integrated wide-angle scanner based on translating a curved mirror of acylindrical shape. , 2013, Optics express.

[15]  P. Griffiths.  Fourier Transform Infrared Spectrometry , 2007 .