A highly miniaturized NDIR methane sensor
Paper in proceeding, 2016
The increasing demand for handheld systems for absorption spectroscopy has triggered the development of microspectrometers at various wavelength ranges. Several MEMS implementations of the light source, interferometer/optical filter, and detector have already been reported in the literature. However, the size of microspectrometers is still limited by the required absorption path length in the sample gas cell. This paper presents a compact MEMS linear-variable optical filter (LVOF) where the resonator cavity of the filter is also used as a sample gas cell to measure the absorption of methane at 3392nm wavelength. The physical resonator cavity length is elongated 62.2-fold, using multiple reflections from highly reflective Bragg mirrors to achieve a sufficiently long effective optical absorption path. Although the LVOF would in principle enable operation as a robust portable microspectrometer, here it is used in a miniaturized NDIR methane sensor for wavelength selection and calibration.
filter
spectroscopy
Optical sensor
methane
spectrometer
fabry-perot
gas sensor
mems
spectral range
microspectrometer
interferometer
Fizeau
mid-IR
Bragg mirror
cavity
Author
N.P. Ayerden
G. De Graaf
Peter Enoksson
Electronics Material and Systems
R. F. Wolffenbuttel
Micro-Optics 2016, Brussels, 4-5 Apr.; (SPIE Proceedings vol. 9888)
0277-786X (ISSN)
Vol. 9888 art. no. UNSP 98880D-978-1-5106-0133-8 (ISBN)
Areas of Advance
Nanoscience and Nanotechnology
Transport
Energy
Subject Categories (SSIF 2011)
Atom and Molecular Physics and Optics
Infrastructure
Nanofabrication Laboratory
DOI
10.1117/12.2225924
ISBN
978-1-5106-0133-8