Catadioptric sensor concept with interlaced beam paths for imaging and pinpoint spectroscopy

Area of Science:

• Optical Engineering
• Spectroscopy
• Sensor Technology

Background:

• Traditional sensors often require separate systems for imaging and spectroscopy.
• Existing systems can be bulky and limited in their adjustable viewing angles and spectral range.

Purpose of the Study:

• To present a novel catadioptric sensor for simultaneous imaging and spectroscopy.
• To achieve a compact design with adjustable viewing angles and broad spectral coverage.
• To demonstrate its utility in practical applications like quality control.

Main Methods:

• Utilized reflective imaging elements for folded and interlaced beam paths.
• Designed a system with only three spherical surfaces for image projection.
• Integrated a miniature spectrometer for spectral analysis of selected scene areas.
• Employed software-based image processing to compensate for anamorphic imaging and distortion.

Main Results:

• Achieved a compact sensor footprint (approx. 90mm x 80mm).
• Enabled simultaneous imaging and spectroscopy from centimeters to infinity.
• Covered a spectral range from 400 nm to 1000 nm (near-infrared).
• Demonstrated effective compensation for optical aberrations via software.

Conclusions:

• The developed catadioptric sensor offers a versatile and compact solution for combined imaging and spectroscopy.
• Its performance is suitable for real-world applications such as product sorting and fruit quality assessment.
• The design highlights the potential of catadioptric systems for advanced sensing tasks.