High-resolution dual-band triple-grating spectrometer for atmospheric CO₂ detection

Area of Science:

• Optical Engineering
• Atmospheric Science
• Spectroscopy

Background:

• Atmospheric carbon dioxide (CO2) detection relies on near-infrared spectral bands.
• High-precision CO2 measurements require high spectral resolution and multi-wavelength data capture.

Purpose of the Study:

• To propose a novel optical design for a high-resolution dual-band triple-grating spectrometer (DTGS).
• To enable high-resolution acquisition of dual-band spectral information for enhanced CO2 detection.

Main Methods:

• Theoretical derivations and simulation validations of the DTGS system.
• Utilizing simultaneous ±1st-order diffraction from gratings for efficient spectral acquisition.
• Employing a grating configuration of one 555 lines/mm and two 1100 lines/mm.

Main Results:

• The DTGS system achieves high spectral resolution (0.072-0.075 nm).
• Successfully detects CO2 weak absorption spectra in dual near-infrared bands (1.556-1.576 µm and 1.578-1.598 µm).
• Overcomes spectral resolution limitations of traditional wide-band measurement systems.

Conclusions:

• The proposed DTGS optical design is effective for high-resolution, dual-band CO2 detection.
• This design enhances system integration and measurement precision for atmospheric monitoring.
• Offers a potential advancement over existing technologies for wide-band spectral measurements.