Analytical method for calculating internal stray radiation from an IR spectrometer based on the view factor

Area of Science:

• Optics
• Spectroscopy
• Optical Engineering

Background:

• Optomechanical components in infrared (IR) spectrometers generate internal stray radiation.
• This stray radiation significantly reduces the instrument's signal-to-noise ratio (SNR) and dynamic range.
• Accurate quantification of stray radiation is crucial for improving IR spectrometer design and performance.

Purpose of the Study:

• To propose and validate a novel analytical method for calculating internal stray radiation in IR spectrometers.
• To establish a mathematical model for view factor calculation applicable to typical optomechanical components.
• To demonstrate the method's ability to quickly and accurately assess stray radiation in IR optical systems.

Main Methods:

• Developed an analytical model based on the view factor to calculate internal stray radiation.
• Established a mathematical model for view factor calculation of common optomechanical components.
• Applied the method to a double-pass long-wave IR spectrometer for validation.

Main Results:

• The proposed method accurately calculated internal stray radiation, with results consistent with simulations (RMS relative error ~11%).
• Experimental validation confirmed the method's accuracy, with test results showing agreement with calculated and simulated data (relative error within 9%).
• The method allows for rapid and precise internal stray radiation assessment in IR systems.

Conclusions:

• The analytical view factor method provides a reliable and efficient approach for calculating internal stray radiation in IR spectrometers.
• This method can be readily adapted for various IR optical systems by adjusting coordinate systems.
• The validated method offers a valuable tool for optimizing IR spectrometer design and enhancing performance by mitigating stray radiation effects.