New design and calibration method for a tunable single-grating spatial heterodyne spectrometer

Area of Science:

• Optics and Photonics
• Spectroscopy
• Instrument Design

Background:

• Spatial heterodyne spectroscopy (SHS) offers advantages for spectral analysis.
• Existing SHS designs can be complex to tune across different spectral ranges.
• Accurate calibration is crucial for reliable spectroscopic measurements.

Purpose of the Study:

• To present a novel, simplified design for a single-grating tunable spatial heterodyne spectrometer (SHS).
• To introduce an improved calibration method for enhanced accuracy in SHS systems.
• To explore the applicability of SHS for broadband measurements and optimize signal-to-noise ratio.

Main Methods:

• A new single-grating design enabling simplified center wavelength tuning (Littrow wavelength).
• Development and application of a novel calibration technique surpassing small-angle approximation formulas.
• Analysis of SHS performance for broadband spectral acquisition.

Main Results:

• The proposed SHS design allows for rapid tuning to arbitrary spectral ranges.
• The new calibration method achieves superior accuracy compared to traditional approaches.
• Strategies for improving signal-to-noise ratio in broadband SHS measurements are identified.

Conclusions:

• The presented tunable SHS design offers enhanced flexibility and ease of use.
• The novel calibration method significantly improves the accuracy of spectral measurements.
• The findings support the broader application of SHS in broadband spectroscopic analysis.