title: On-Chip Micro-Electro-Mechanical System Fourier Transform Infrared (MEMS FT-IR) Spectrometer-Based Gas Sensing.
abstract: In this work, we study the detection of acetylene (C2H2), carbon dioxide (CO2) and water vapor (H2O) gases in the near-infrared (NIR) range using an on-chip silicon micro-electro-mechanical system (MEMS) Fourier transform infrared (FT-IR) spectrometer in the wavelength range 1300-2500 nm (4000-7692 cm(-1)). The spectrometer core engine is a scanning Michelson interferometer micro-fabricated using a deep-etching technology producing self-aligned components. The light is free-space propagating in-plane with respect to the silicon chip substrate. The moving mirror of the interferometer is driven by a relatively large stroke electrostatic comb-drive actuator corresponding to about 30 cm(-1) resolution. Multi-mode optical fibers are used to connect light between the wideband light source, the interferometer, the 10 cm gas cell, and the optical detector. A wide dynamic range of gas concentration down to 2000 parts per million (ppm) in only 10 cm length gas cell is demonstrated. Extending the wavelength range to the mid-infrared (MIR) range up to 4200 nm (2380 cm(-1)) is also experimentally demonstrated, for the first time, using a bulk micro-machined on-chip MEMS FT-IR spectrometer. The obtained results open the door for an on-chip optical gas sensor for many applications including environmental sensing and industrial process control in the NIR/MIR spectral ranges.
authors.affiliation: Faculty of Engineering, Ain-Shams University, Abbassia, Cairo, Egypt Mazen.Erfan@eng.asu.edu.eg.
authors.forename: Mazen
authors.initials: M
authors.lastname: Erfan
authors.affiliation: Faculty of Engineering, Ain-Shams University, Abbassia, Cairo, Egypt Si-Ware Systems, Heliopolis, Cairo, Egypt.
authors.forename: Yasser M
authors.initials: YM
authors.lastname: Sabry
authors.affiliation: Faculty of Engineering, Ain-Shams University, Abbassia, Cairo, Egypt.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Sakr
authors.affiliation: Si-Ware Systems, Heliopolis, Cairo, Egypt.
authors.forename: Bassem
authors.initials: B
authors.lastname: Mortada
authors.affiliation: Si-Ware Systems, Heliopolis, Cairo, Egypt.
authors.forename: Mostafa
authors.initials: M
authors.lastname: Medhat
authors.affiliation: Faculty of Engineering, Ain-Shams University, Abbassia, Cairo, Egypt Si-Ware Systems, Heliopolis, Cairo, Egypt.
authors.forename: Diaa
authors.initials: D
authors.lastname: Khalil
keywords: Gas detection; MEMS technology; MIR spectrometer; NIR spectroscopy; micro-electro-mechanical systems; micro-optical bench technology; mid-infrared spectrometer; near-infrared; portable spectrometer; spectral-based sensor