Cascaded, self-calibrated, single-pixel mid-infrared Hadamard transform spectrometer

Area of Science:

• Spectroscopy
• Optical Engineering
• Infrared Technology

Background:

• Mid-infrared (mid-IR) spectroscopy is crucial for material analysis.
• Existing spectrometers can be bulky and expensive, limiting field applications.
• Hadamard transform spectroscopy offers potential for compact designs.

Purpose of the Study:

• To develop a single-pixel mid-infrared Hadamard transform spectrometer.
• To demonstrate its capability for accurate spectral recovery.
• To assess its potential for portability and cost-effectiveness.

Main Methods:

• Designed and fabricated a single-pixel mid-IR Hadamard transform spectrometer.
• Utilized dual cascaded encoding regions (2875–3500 nm and 3500–4077 nm).
• Employed a reverse spectrometer for signal collection and a 635 nm laser for calibration.

Main Results:

• Successfully recovered mid-IR spectra within the designed wavelength range.
• Demonstrated accurate spectral recovery through experimental validation.
• The spectrometer achieved dimensions of 200 × 200 × 84 mm and a weight of 1.8 kg.

Conclusions:

• The developed spectrometer is portable and potentially low-cost.
• It is suitable for field applications requiring mid-IR spectroscopy.
• This technology advances accessible IR spectral analysis.