Optical path coupling optimization analysis of compact flat circular multi-pass cell for hydrogen leakage laser...

Area of Science:

• Optics and Photonics
• Chemical Engineering
• Materials Science

Background:

• Reliable hydrogen monitoring is crucial for fuel cell safety, especially in confined environments.
• Conventional detection methods suffer from optical loss, low sensitivity, and slow response times.
• Existing technologies struggle to balance optical path length with compact cell volume.

Purpose of the Study:

• To design a miniaturized multi-pass cell for enhanced hydrogen detection in fuel cells.
• To overcome limitations of conventional methods by maximizing optical path length and irradiance utilization.
• To enable direct, in situ hydrogen monitoring with improved spatial efficiency and response time.

Main Methods:

• Developed a miniaturized flat circular multi-pass cell with a planar reflector array and semi-closed housing.
• Optimized incident and reflection angles for a spiral two-layer beam trajectory.
• Investigated polygonal reflection layouts, identifying the 20-spike geometry for efficiency.
• Performed tolerance analysis and beam divergence simulations.

Main Results:

• Achieved a 1.54 m optical path length within an 18.85 ml cell volume.
• The 20-spike geometry resulted in only 8.743% signal attenuation.
• Enhanced average irradiance by nearly threefold compared to traditional cells.
• Demonstrated stable beam propagation and identified optimal beam divergence parameters.

Conclusions:

• The proposed miniaturized multi-pass cell effectively enhances hydrogen detection sensitivity and response time.
• This design offers a compact, efficient solution for in situ hydrogen monitoring in fuel cell systems.
• The technology improves safety and performance by enabling reliable real-time gas analysis.