Off-axis aberration correction for a reflective coded aperture snapshot spectral imager.

Area of Science:

• Optics
• Image processing
• Spectroscopy

Background:

• Coded aperture snapshot spectral imagers (CASSI) offer high flexibility but suffer from off-axis aberrations.
• Digital micromirror devices (DMD) provide high-quality intensity modulation in reflective CASSI systems.
• Off-axis aberrations degrade the image quality of DMD-based reflective CASSI.

Purpose of the Study:

• To analyze the formation of off-axis aberrations in DMD-based reflective CASSI.
• To propose and validate an optical-axis-shift (OAS) configuration to compensate for off-axis aberrations.
• To enhance the performance and image quality of CASSI instruments.

Main Methods:

• Analysis of off-axis aberration formation in reflective CASSI systems.
• Development and implementation of an optical-axis-shift (OAS) configuration.
• Experimental validation and performance evaluation of the proposed OAS design.

Main Results:

• The proposed OAS configuration effectively eliminates off-axis aberrations in DMD-based reflective CASSI.
• Reconstructed spectral images show an average improvement of approximately 2.8 dB in peak signal-to-noise ratio.
• The OAS design demonstrates superiority over other aberration alleviation methods.

Conclusions:

• The optical-axis-shift (OAS) configuration is a highly effective solution for mitigating off-axis aberrations in DMD-based reflective CASSI.
• The proposed design is easily implementable using commercially available components.
• This work provides a foundation for developing high-performance CASSI instruments.