Compact Shortwave Infrared Imaging Spectrometer Based on a Catadioptric Prism

Area of Science:

• Optical Engineering
• Spectroscopy
• Imaging Technology

Background:

• Traditional spectrometers often face limitations in terms of size and complexity.
• Developing compact imaging spectrometers is crucial for field applications and portable devices.
• Aberration correction and dispersion enhancement are key challenges in spectrometer design.

Purpose of the Study:

• To demonstrate a novel compact prism imaging spectrometer method.
• To reduce the overall volume of imaging spectrometers.
• To simplify the optical design process for non-coaxial spectrometers.

Main Methods:

• A catadioptric curved prism was integrated into the secondary mirror position of the spectrometer.
• A mathematical model of the prism and spectrometer system was derived.
• The design focused on aberration balancing, dispersion width enlargement, and volume reduction.

Main Results:

• A compact shortwave infrared imaging spectrometer (0.95–2.5 μm) with a 16° field of view was designed.
• The spectrometer length was reduced by 40% compared to systems with similar specifications.
• Laboratory testing confirmed excellent optical performance.

Conclusions:

• The proposed catadioptric curved prism method enables significant volume reduction in imaging spectrometers.
• The mathematical model provides an optimal initial structure, simplifying optical design.
• This technique is effective for developing compact, high-performance spectrometers for various applications.