A photonic microsystem for hydrocarbon gas analysis by mid-infrared absorption spectroscopy

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Publication Year
2017
Language
English
Research Group
Electronic Instrumentation
Pages (from-to)
1052-1055
ISBN (electronic)
978-1-5090-5078-9
Event
MEMS 2017 (2017-01-22 - 2017-01-26), Rio Las Vegas Hotel and Casino, Las Vegas, NV, United States
Downloads counter
183

Abstract

This paper demonstrates the functional integration of a linear variable optical filter (LVOF) and a gas cell at the wafer level, i.e. a gas-filled LVOF, where the resonator cavity of the filter is also used for storing the gas sample. A mm-level effective optical absorption path length is achieved from a μm-level physical path length, by exploiting multiple reflections from highly reflective Bragg mirrors and the high-order operation of the filter. The wideband spectral response of the device is ensured by using a tapered cavity, where the cavity length changes linearly along the length of the filter. Therefore, combined with a detector array and a light source, the gas-filled LVOF enables wideband operation and long absorption path in a single MEMS device, thus ensuring a highly sensitive on-chip gas absorption microspectrometer.