Optical design of temperature-insensitive afocal attachments.

Area of Science:

• Optical Engineering
• Infrared Technology

Background:

• Afocal optical attachments, often Galilean telescopes, are used as range extenders in thermal imaging.
• These attachments increase the effective focal length (EFL) of thermal imagers (TI), enhancing resolution.
• Maintaining optical performance across operating temperatures is crucial for athermalization in extended TI systems.

Purpose of the Study:

• To discuss optical design aspects of afocal optics for mid-wave infrared (MWIR) applications.
• To develop a mathematical model for selecting athermal and achromatic afocal solutions.
• To present optical designs verifying the developed mathematical model.

Main Methods:

• Development of a mathematical model using paraxial calculations.
• Selection of material combinations for athermal and achromatic afocal solutions.
• Presentation of optical designs for model verification.

Main Results:

• A mathematical model for designing athermal and achromatic afocal optics in MWIR systems was developed.
• Suitable material combinations were identified through paraxial calculations.
• Demonstrated optical designs validated the model's effectiveness.

Conclusions:

• The developed mathematical model aids in designing athermal and achromatic afocal solutions for MWIR thermal imaging.
• The study provides a foundation for enhancing thermal imaging systems with range extenders.
• Optimized afocal designs ensure sustained optical performance across temperature ranges.