Design of simplified long wavelength infrared imaging systems based on optical-digital joint optimization

Area of Science:

• Optics and Photonics
• Infrared Imaging Technology

Background:

• Long-wavelength infrared (LWIR) systems provide essential capabilities like deep penetration and passive operation.
• High costs associated with specialized materials (e.g., germanium, zinc selenide) hinder widespread adoption of LWIR systems.

Purpose of the Study:

• To develop a joint optimization method for LWIR system design that integrates diffraction effects.
• To reduce system complexity and cost while maintaining high imaging performance.

Main Methods:

• Incorporated diffraction effects directly into the optical design process.
• Developed a tolerance analysis method using the structural similarity index (SSIM) for robustness evaluation.
• Presented design examples for both coaxial and off-axis freeform LWIR systems.

Main Results:

• Demonstrated system simplification through reduced element count while preserving imaging quality.
• Validated the effectiveness of the proposed joint optimization method with practical design examples.
• Quantitatively assessed system robustness against manufacturing and assembly tolerances.

Conclusions:

• The proposed joint optimization method effectively simplifies LWIR system design and reduces costs.
• The tolerance analysis provides a quantitative measure of system robustness.
• Experimental validation confirms the practical applicability and performance benefits of the developed approach.