Stray light correction on array spectroradiometers for optical radiation risk assessment in the workplace

Area of Science:

• Optical Physics
• Occupational Health and Safety

Background:

• European directive 2006/25/EC mandates workplace optical radiation exposure assessment.
• Array spectroradiometers are crucial for measuring optical radiation but suffer from stray light inaccuracies.
• A NIST-developed stray light correction matrix using tunable lasers exists but is costly.

Purpose of the Study:

• To implement a cost-effective stray light correction method for spectroradiometers.
• To reduce reliance on expensive tunable lasers for stray light correction.
• To validate the accuracy of corrected spectroradiometers for workplace risk assessment.

Main Methods:

• Developed a stray light correction matrix using nine low-power lasers.
• Employed interpolation and extrapolation for matrix completion.
• Compared corrected CCD spectroradiometers against a scanning double monochromator reference device.

Main Results:

• Reduced spectral stray light by one to two orders of magnitude, consistent with NIST findings.
• Demonstrated acceptable uncertainty levels for workplace risk assessment.
• Identified CCD detectors with enhanced UV sensitivity as yielding the best results.

Conclusions:

• The implemented method effectively reduces spectral stray light in spectroradiometers.
• Corrected spectroradiometers provide reliable data for workplace optical radiation risk assessment.
• Validation against a scanning double monochromator is essential before workplace application.