Fiber-coupled, UV-SWIR hyperspectral imaging sensor for combustion diagnostics

Area of Science:

• Optical Engineering
• Combustion Diagnostics
• Spectroscopy

Background:

• Remote sensing of flame emission is crucial for combustion analysis.
• Existing methods may have limitations in spectral resolution and spatial coverage.
• Hyperspectral imaging offers detailed spectral information for combustion studies.

Purpose of the Study:

• To develop a fiber-coupled hyperspectral imaging sensor (HSIS) for remote, 2D flame emission detection.
• To characterize the performance of a novel 2D-to-1D fiber-optic array for UV-SWIR measurements.
• To demonstrate improved fuel/air ratio measurements using spectrally resolved chemiluminescence.

Main Methods:

• Development of a fiber-coupled HSIS utilizing a 1024-fiber 2D-to-1D array.
• Transmission of flame emission signals via a 3-m UV-grade imaging fiber bundle.
• 2D spectrally resolved measurements of CH*, OH*, and C2* distribution in premixed laminar flames.

Main Results:

• The HSIS operates from UV to SWIR (300-2400 nm) with high UV transmission.
• A compact 2D-to-1D fiber array (1024 fibers, <5 cm) was successfully designed and characterized.
• Demonstrated improved chemiluminescence-based fuel/air ratio measurements with spectrally resolved detection.

Conclusions:

• Fiber-coupled HSIS is a feasible technology for remote, 2D flame emission analysis.
• The developed sensor is suitable for practical applications in gas-turbine engine test facilities.
• This approach enhances combustion diagnostics capabilities with limited optical access.