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

Area of Science:

• Optoelectronics
• Microelectromechanical Systems (MEMS)
• Gas Spectroscopy

Background:

• Semiconductor and MEMS technologies enable miniaturized optical devices like spectrometers and photodetectors.
• Integrating a gas cell is crucial for in-situ gas analysis using optical absorption spectroscopy.
• A complete gas analysis system-on-chip requires seamless integration of all components.

Purpose of the Study:

• To propose design guidelines for a MEMS-fabricated gas cell.
• To experimentally validate the performance of the miniaturized multi-pass gas cell.
• To demonstrate the feasibility of a fully integrated gas analysis system-on-chip.

Main Methods:

• Designing a circular multi-pass gas cell using MEMS technology.
• Utilizing simulation results to optimize gas cell dimensions based on micro-fabrication constraints.
• Coupling the MEMS gas cell with a MEMS-based spectrometer for spectral signature measurement.

Main Results:

• The proposed modeling scheme determined optimal dimensions for the micro-fabricated gas cell.
• Successful measurement of the carbon dioxide spectral signature was achieved.
• Demonstrated the integration of a MEMS gas cell with a MEMS spectrometer.

Conclusions:

• MEMS technology is suitable for fabricating miniaturized multi-pass gas cells.
• The integrated system enables effective in-situ gas analysis.
• This work paves the way for compact, on-chip gas analysis systems.