Silicon Multi-Pass Gas Cell for Chip-Scale Gas Analysis by Absorption Spectroscopy

Abstract

Semiconductor and micro-electromechanical system (MEMS) technologies have been already proved as strong solutions for producing miniaturized optical spectrometers, light sources and photodetectors. However, the implementation of optical absorption spectroscopy for in-situ gas analysis requires further integration of a gas cell using the same technologies towards full integration of a complete gas analysis system-on-chip. Here, we propose design guidelines and experimental validation of a gas cell fabricated using MEMS technology. The architecture is based on a circular multi-pass gas cell in a miniaturized form. Simulation results based on the proposed modeling scheme helps in determining the optimum dimensions of the gas cell, given the constraints of micro-fabrication. The carbon dioxide spectral signature is successfully measured using the proposed integrated multi-pass gas cell coupled with a MEMS-based spectrometer.

Near-Infrared Spectroscopic Gas Detection Using a Surface Plasmon Resonance Photodetector with 20 nm Resolution

“…One is to increase the interaction optical path length between the gas and the light in a gas cell. There are several researches to increase the sensitivity of gas sensors by creating a multiple reflection structure inside a small MEMS cavity . Small-sized gas cell is becoming feasible.…”

“…There are several researches to increase the sensitivity of gas sensors by creating a multiple reflection structure inside a small MEMS cavity. 28 Small-sized gas cell is becoming feasible. Another, elongation of the wavelength into the mid-infrared range, where gas absorption is much stronger than those in the NIR region.…”

Critical analysis of in-plane free-space light beam coupling using photonic curved micromirrors

“…4.2. Despite this, it has been used recently in different applications such as a multi-pass gas cell for gas analysis 68 and visible-laser generation on a silicon chip 69 due to the use of a slotted cylindrical micromirror in which its coupling efficiency is studied in detail in Ref. 70.…”

Editorial for the Special Issue on IMCO 2019

“…In this Special Issue, 10 papers present integrated, multifunctional physical and chemical sensors based on different platforms such as silicon gas cells [ 1 ], microchips [ 2 , 3 ], and various forms of optical fibers [ 4 , 5 , 6 , 7 , 8 , 9 , 10 ]. These studies well demonstrate the beauty of optofluidics by integrating the microfabricated structures and the micro-optics for high sensitivity and specificity of sensing.…”