Accurate and fast stray radiation calculation based on improved backward ray tracing

Area of Science:

• Optical Engineering
• Thermal Sciences
• Computational Physics

Background:

• Stray radiation analysis is critical for optical system performance, particularly in cryogenic infrared imaging.
• Traditional backward ray tracing methods can lack accuracy and computational efficiency.
• Forward ray tracing is often computationally intensive for complex systems.

Purpose of the Study:

• To develop an improved backward ray tracing method.
• To enhance accuracy and reduce computational cost in stray light analysis.
• To validate the method for cryogenic infrared imaging systems.

Main Methods:

• Incorporated ray orders and weight factors into backward ray tracing.
• Designed a sequential and recurring process for tracing and calculating different order stray lights.
• Excluded irrelevant surfaces and rays to optimize computation.

Main Results:

• Significantly improved accuracy compared to traditional backward ray tracing.
• Demonstrated effectiveness in stray radiation analysis for a cryogenic IR imaging system, with results matching real-world irradiance distributions.
• Achieved at least a 2-orders-of-magnitude reduction in computation compared to forward ray tracing for similar accuracy in narcissus calculations.

Conclusions:

• The improved backward ray tracing method offers superior accuracy and computational efficiency.
• This method is highly effective for stray radiation analysis in cryogenic infrared imaging systems.
• The technique provides a valuable tool for optimizing optical system design and performance.